well... indica might be better for sog...
sog you're really looking for a mom plant that will clone well (you don't want to be wasting time/space on males so seeds are out of the question kinda...) and one that produces a nice big fat cola... cuz that's what you're aiming for in sog... a lot of giant single cola's
BUT
sativas because they are generally so stretchy and tall if grown from seed, also work a lot better in sog than if nothing special is done with them... you might not get single cola's but with some lollypopping (see canna's sig for a link on how to) you will get a few real nice cola's of headspinnin sativa
this all make sense?