I can't see anything glaringly wrong with your kit concept.
It is very individual however.
A couple of tangendental thoughts......
The DDrum Dominion is a mid-level (kinda budget) set isn't it?
Therefore, perhaps you are going to want to upgrade to a pro level kit at some point, especially as you seem to be a deep thinker on set-ups and quite particular about what you want.
In which case, this custom kit your planning is not going to be easy to move on (sell), as it's a very particular set-up from a less than mainstream manufacturer.
If I were in your boots I probably wouldn't be buying a new kit from Guitar Center - the staff there are notoriously unknowledgeable about the gear they sell. I would be speaking to a custom builder.....perhaps like Pork Pie, but there are other, cheaper priced,  custom builders out there.
You'll get a better sounding kit, a better level of advice and a really personal service, hopefully leading to exactly the right kit for your needs. I mean you seem to have some really basic problems deciding on this kit anyway, tom size for example.
I'm not for buying brand new kits anyway, but that's another story.
I'm not keen on 20 x 20" bass drums either.
However, in your case, I'd look out for an old 20", 13 & 16" kit (Slingerland, Ludwig, Gretsch). There are a bunch out there and they sound stellar. Then add a used 26" bass drum from the same manufacturer.
All that aside, I'd advise you speak to a custom builder who really offers a personal service and scratch the idea of custom designing a mid-level kit with only the advice of Guitar Center to go by.

thanks for the replies guys.
 
I'm not really going off of advice from guitar center, but I have to go through them to order the kit.
 
 The biggest thing for me is budget. I looked at doing a custom kit a couple years ago. I started off looking at underground builders such as conaway drums and some others. But i came to the realization that It would pretty much be around $1800 and for a little more, I could have a custom name brand set such as C&C. But then i bought a car... 
 
So now when i saw the ddrum dominion kit at GC for $800 and looked at the quality of the components, i realized thats a pretty good deal, and the only reason its so cheap is cause ddrum is trying to get their name "out there." But alas, $800 is still too much, (cause i would still need to buy new heads, and bags/cases)

So the kid (G.C) had the idea of just ordering the shells i wanted from the kit... (the 20x20,8x12, 12x16)
 He got back to me a couple days later with a price of $400 but I wouldn't get it till may.
 
So now i'm thinkin i can get a little more creative and pick shells from the different pre-packs and get exactly what i want. and it can't be more than like $600... I know I can't even build a kit myself for that much...
 
And the idea about the large footprint... this is true. But my idea is kinda have two kits... but they'd share the same toms... so.. in the right situation, i would use just the 26" and other times, use the 20"

alright, I'll probably stick with the traditional 8x12" tom.
 
and i'm second guess the 16x26" bass.. I'm thinkin it may be too messy... Would an 18x24" be better?
 
 
The reason i want a 20x20 so bad is cause i used to work at one of the countrys largest drum shops and we had a ocdp kit in there with a 20x20 and it was the best sounding bass there... but it wouldn't be right in loud, pounding rock situations... thats where the 24" comes in... its much more powerfull than a 22" and slightly boomier... but not as messy as a 26"....
 
 my only fear is that the 24 and 20 are gonna be too similar to necessitate owning both...

What specific purpose do you have in mind that would necessitate 2 very different kick sizes? If we know that we can probably help you choose your secondary kick drum too. Also, keep in mind that it may not have been just the dimensions of that OCDP drum that made it sound so good, and a ddrum kick of the same size may not blow you away like the OC one did.

If you put a SKII/Reg head combo on that kick it will make it sound a little deeper. I'm getting a new ddrum kit and chose an 18x22 over an 18x24. I was really wanting the 24 originally, but after hearing what the 18x22 sounded like with a SKII/Reg combo I realized that it was just what I was looking for. I already own a 14x24 that I can use if I just have to have that bigger sound, but with that head combo you can get a 22 to sound really nice- and a 20 for that matter.

$400 is pretty good for just three shells from the Dominion line. I'm actually surprised. I guess GC has the mass buying power to do that. I'm getting a new ddrum Diatribe 6pc kit and without hardware it will run me around $800 to $850. I'm getting the new blue sparkle lacquer which is extra. I'm also ordering through a local mom n pop shop so I figure their price will be a little more than GC- but I like supporting this shop. It will probably take about two months to get 5 pieces of my kit, then an additional month for my extra tom but I think it's worth it.

I think a 26" kick would be a lot of fun though. haha!

From your diagram it looks like you want to use both bass drums on the one gig.
That would certainly be applicable for a The Roots kinda gig.

I've always been intrigued by the 20"depth x 24" diameter kicks! That spells ROCK to me!

The Ddrum stuff looks nice. The finishing is great. Ive only heard the ash which i dont like but thats me. Ive heard customer service at Ddrum is horrible but what kind of problems will you ever have?, most likely none. If you need edge work done on them O.C.D.P. does great edges cheap.

I think youll be happy with the kit of your choice from Ddrum.