Best price, and best place by far to buy from, for the Neu motors is from Mike at www.rc-monster.com
He has the motors and he knows what you are doing with them. Anyone else selling them will be helicopter/plane shops... they won't know jack about anything. These motors can be hard to get because they are low production/high end pieces. They are the best motors you can buy.
They have the finned cans at $225 for the 1512 and $280 for the 1515. That's what I paid.
If you find a 1515 for $260 that's a good deal.... the finned cans are normally $20 extra. But Mike doesn't charge extra for the finned.
Here's the motor sizes etc. http://www.neumotors.com/neu1500.html
I have the 1512 1.5y but I would recomend the 2.5d also... almost the same motor, just a little higher rpm. The 2000kv is just about right for 4s lipos.
You can get the Mamba Max esc for $135 or less.
Ubec is a voltage converter (battery eliminator circuit)... you can also use a rx pack. The point is not to use the Mamba's buit-in bec with these setups... 4s lipos.
You don't need to go to finedesign to do a bl conversion.... in fact if you do, it handicaps what you can use, etc
If you do it yourself you have control over how it's set up etc and you can spend your money on better electrics instead.