I am not sure if you are looking to go bitter IPA style or smooth APA style, with a rounded bitterness. It sounds like you are going for something a little more rounded.
The last 4 APA's I have done have all been late hop additions. The last 2 have been SMASH beers, with Citra in one and Columbus in the other (different base malts in each). For my 5 gallon batch I used 8 ounces (ya heard!), all within the last 20 mins of the boil with an ABV of just about 5%. The Citra one was awesome. (Citra is not a very stable bittering hop, next time I will use something different Centennial would be perfect- for the 20 min addition). The Columbus is a little more dank, still really good but the Citra one.... Man, flavor, aroma, smooth bitterness...... I plan on doing another SMASH with the same hop schedule with yet a third base malt and add either Simcoe and Centennial.
So, I like the idea of splitting the batch and do one with Citra, one with Simcoe. But, I also like the idea of trying to smell the difference between the two batches with different dry hops. Whats great is, this is completely up to you. My advice? If you want the flavor and aroma to ring through, do every hop addition within the last 20 minutes. Don't be afraid if an IBU calculator tells you your IBU's will be in the hundreds. My Citra SMASH was supposed to be 148ish IBU and it was smooth. I would up your hops to around 5 ounces at least, and dry hop with more than only one once. One once doesnt seem to generate a lot of aroma. So you could nix the whole dry hop and just flip-flop your last hop additions, if you decide to split the batch. Do like 1 oz Citra at 10, then 1 oz Simcoe at 5, 1 and one more at flameout. Then, do 1 oz of Simcoe at 10, then 1 oz of Citra at 5, 1 and flameout. If you hit your wort with late hop additions (in the last 10 mins, down to flameout addition), I promise you will get a fantastic smelling beer.
I read the following article, was skeptical but wanted to try it anyway. I will more than likely never do a 60 minute addition again on an APA.
Cheers and keep us posted. Welcome to the stress of recipe development. (its not stressful at all once you do it a few times, BTW. If you screw it up, you'll still have beer, right?)
http://www.mrmalty.com/late_hopping.php