I have a motor from
Electric Rider choosing the Phoenix Cruser, and am extreamly happy with it, it's beefy, and gives a solid push when you hit the throttle, the person who owns the insane a cycle apparently works for electric rider, a friend has the same phoenix motor on a cat trike and is able to pull a bob trailer full of produce up hills at 25mph, we both have the 36v DeWalt lithium battery packs, best price I found was on Ebay for around $100 each new, but the price is slowly droping, and they have a warenty.
I've talked to other people who bought motors from goldenmotor.com and liked them, untill they rode other electric bikes.
I also used to own a ZAP electric bike kit... still own it in fact for 14 years, it still works, 12mph for about 10 miles, everything still works it just needs a new battery, I might be willing to sell it.