If I have an amp head, would i need a cabinet? This is purely for recording not live play.
mic'ing a cab will typically always sound better than going directout, imo...

^like he said you'll need a load so that you don't blow the head, so you can either buy a cab and either mic it or go direct out(plus you could actually use the amp for more than recording), or you can buy a dummy load and just go direct out.