Wings;
If you look at the pictures in this post and the other post with the air filter pictures you can see my carb. The ZDZ's are mounted inverted. the needles and choke shaft point up. All i did was silver solder some 4-40 cap screws to the top of the needles so they were just below the top of the cowl. On the top of my cowl i have 3 - 1/16" holes right above the needles. and to be honest, i didn't even have to do that as once the eng. was set i didn't have to touch them. To choke it i just use a 4-40 allan wrench. Same to adjust the needles. Some people use a micro servo to activate the choke and also as a emergency shut off.

Engine mounting:
If you can mount a side carb motor you can mount a rear carb just as easy. The only difference is that you now have a hole in the fire wall where the carb passes thru. Most airplanes that are designed for gas engs have the eng mounted to a box, which simplifies mounting. If you have a flat firewall, i block off the area just in front of where the wing bolts on. This stops any prop blast air from entering the inside of the fuse and possibly blowing your covering off. As for fuel entering the fuse i've never had a problem unless you flood the eng. (rare once you catch on to starting your eng.)
Check out pictures of different models and you can see how they have mounted their engs. mufflers,etc. You can get some great ideas from them.