I made one a while back, and it has had plenty of power and works great i am very pleased with it. I have only done ducks with it so far but i will be using it on some geese within the month. I bought a fan motor from grainger that runs at 1550 Rpms i also bought a coupling from grainger. I then put it all together and it cost me around $60 total. I have used a coarse wheel, fine wheel, and a nylon wheel with it but i favor the fine wire wheel the best. The nylon wheel works great for softer skinned birds like teal and wood ducks though. I built mine taller and at an angle to give me a better view and more room to work with for geese and turkeys.
The wheel sticks out three inches and it is 14 inches from the bottom, which again gives me a good amount of room to work with. Did a mallard with it yesterday in under ten minutes. I havent had any problems with it yet and i really enjoyed making it. Best thing about making one yourself is that you can customise it to fit your needs and wants, not to mention it can save you a ton of money. What your planning on making sounds pretty good to me. The motor i have runs good even with a fair amount of pressure. I would just suggest if you are planning to use it for bigger birds or you think you would in the future that you make it a little bigger then thoose two mentioned. Good Luck