Wraith 7K works great on 2S lipo. It is a 280S can motor: 24mm diameter and 35mm long. The shaft is 2mm in diameter so you can use RC18 and MiniT pinions.
http://www.b-p-p.com/proddetail.php?prod=db_wraith
YPIN 5100KV works better. It is a 380S class with 28mm diameter and 37mm long with 1/8 shaft son you can use standar 48p pinions.
http://cgi.ebay.com/New-KV-5100-Inne...sid=p1638.m118
TowerPro 2415-03T is an outrunner 380 class. Very cheap and fast. 4850Kv and 1/8 shaft and it's very esay to open to clean the dust.
https://www.unitedhobbies.com/UNITED...idProduct=6261
Just my 2 cents...