What sort of flying are you looking for?
I ask because it makes a big difference on the available power you want.
For low speed climbs you could go 200 watt/kg and get 3 launched on a light and cheep setup.
If you want a 30+ m/sec climbs you should be looking for 2kW which means bigger, more expensive motors and big batteries to provide the current for these monsters.
In any case, fitting an outrunner in the very narrow fuses is usually not possible unless you are going for really underpowered climbs.
You will probably need a geared motor and you can look at the Hacker B40 and B-50, Neu, Kira combinations and micro edition setups:
If you tell me what you are looking for, maybe I can help you with something a little more focused