Coulter_Dean,
Don't feel bad about choosing the OS 32F!!!! It's a great engine and will work just fine in your Stickit IV! With or without a MCP, I'd recommend starting with a 10x4 prop.

But just don't rule out the OS 40FP in a Stickit because of it's reputation as a cheap but low powered 40. Yes, it is cheap....and yes, it is low powered for a 40. But when you start comparing the 8.75 ounce 40FP to other engines in the same weight class, then the 40FP starts looking pretty good compared to those expensive ball bearing 25 to 32 size engines......especially once you get rid of that extremely restrictive stock 40FP muffler.

Add a MCP to the 40FP, and it starts generating some serious power for such a lightweight and inexpensive engine. In a Stickit IV, the 40FP w/MCP will equal or outperform a 32F with a stock muffler. Once you put a MCP on the 32F, then the 32F will put out a little more power than the 40FP w/MCP....but the difference inflight isn't all that great.