Slow flight is indeed possible. Remember that most of your 3D manuvers are performed at high power settings using the prop that best provides thrust, not speed. The same 3D manuvers are performed at much higher than normal angles of attack.

In this case, power and radio mix set up will be everything. Look for an engine that provides as much power as possible at the lowest possible weight. I'm not generally in favor of two strokes for high alpha flight, but most of the 4 strokes that will provide the power you will want will be too heavy. Lighter IS better! A really strong 60 to 75 will do fine.

Keep your props in the 12x4 to 13 1/2x 5 pitch range. Try to keep your fuel tank size at 12 ounces or less. You won't have as much flight time as you might like (about 8-10 minutes), but your plane will be lighter. Don't use higher than 15% nitro fuel in the attempt to find more power. Unless you are running a tuned pipe (more weight), all you will do is wear your engine out sooner. I think you will be happy with this set up.

Good Luck!

Silversurfer