i wouldnt grow pure sativas as they take way too long to flower some at 120 days thats long man
wether or not you can grow em indoors reliably i dont really know but i wouldnt recomend it
tell him to try get some new style sativa strains they take the same flowering time as usual indica/sativa strains most are early maturing and they are reccomended for indoor use to
the seeds you can get feminised relativly cheap and non fem even cheaper
check out this site www.femaleseeds.nl
has a few new style sativas on it
grapefruit sound nice