I have the beefed up housing which retails for $185 www.evdeals.com
The superkids upgrade combo which includes the 1000w Powepack motor and 72v35a crystalite controller. Cost me about $400 if I recall.
Seriously badass setup for the synergy. I ran this on 15s8a nanotechs. Stock gearing would peak at 1800w 31mph on the flat. I replaced stock gear with a 60t to tone down the watts. This gave me 1500 peaks with 27mph. Got to speed much quicker and much more torque. The motors protective case has some chipped cooling fins as I wiped out crossing wet railroad tracks...
Downside. This is so powerful it eats the soft metal sprockets after a thousand miles or less. So you will need a stronger sprocket then stock. Perhaps hardened steel.
I just got an ODK Utility bike and I need to equip it. Looking for cash (paypal)or trade. I need a rear hub motor for a 20" wheel. HS3540 or a 9c would be ideal, I really want a dd hub so no gears. An infineon 12fet is needed. A cycle analyst, CADP or CADPS.
As far as price...... hows $400 Plus shipping sound.