Twinstar!!
Also, since you are in the wing, it is very easy to modify the nacelles to cram 8 oz tanks. I've done this to 2 twinstars and my current twin star has 8 oz tank in each wing. A much much better improvement in flight them than the puny tanks they have in there.
I think 2 inches on each wingtip would help with the extra weight of retracts.