As I recall, the leading edge of the wing ends up close to the firewall to keep the plane frombeing nose heavy.

Cutting a bladder compartment into the wing seems like a good idea. It's the hard tanks that are hard to mount. As I recall, the combaters put the bladder behind the spar as there wasn't enough wing ahead of it. These were very early versions of the Hacker. The airfoil cross section may have changed. You might ask Phil at The Corehouse.

I've used "floppy bladder tanks" made of baby bottle liners. They work fine but take up a lot of space that a half A doesn't have (and are ugly and draggy). They will tend to lean out during the run. Do you know of a compact pressureless bladder?