I'm gonna be honest: selling a perfectly good combo amp that's head and shoulders above most other amps in its class, in terms of both quality and volume, just because you'd like a head and a cab instead is a bit daft in my opinion. Unless there's a particular model of head and a particular cab that you have tried and know you like more than the Twin, and can get for less than the Twin is worth, then I would say that you'll most likely regret it.
Don't mean to burst your bubble or anything, just saying, if you actually don't like the Twin or know for a fact it isn't suitable for what you're playing, then by all means replace it, but just 'cause you'd rather have a head and a cab doesn't seem like a good enough reason to me, especially with an amp as decent as a Twin.
