For wire/connections I use silicon/wet noodle wire purchased from robotmarketplace.com I think robochallenge are also starting to stock wet noodle wire now though... Drop grant a pm.

Connectors I use deans connectors, there rated upto 70a contin, you can pick them up cheaply of eBay/robochallenge

As Gary said a speed 900 would be a good alternative... But if uve got a bit more weight spare you could go for a car fan motor. On 24v there really good. And better yet cheap of eBay/scrap yard