I found a 600 to be great in a 4x4. In a 5x5, 1000 strikes me as ideal. cnid say go with a 600w lumatek. 1000w can be too hot and i dont think it whould be a good choice in that size tent. id say find an aircooled hood thats square
btw...don't listen to anything this guys says. he only pulled 1.35gpw off 4000w of lighting as a relative newb. pathetic.i got the raptors, the only thing i prefer the raptor over the xxxls are they seem to be more air tight. both shoot a really nice foot print. you can cover a 5x5 with that no problem with a 1k
magnum xxxl for sure IMO