I'd recommend the Line 6 Toneport UX-1. It's a relatively cheap interface with Pod Farm, which works great and gives very decent tones. Also has the capacity to record bass and vocals.
As for sequencing software you could try Cakewalk Guitar Tracks. It's what I use and it's good if you haven't got the money for something like Logic.
This actually did cross my mind, and the more I think, it's probably the route I'll take. Can the Toneport be used with the line out from my amp?
Also, with Steven Slate drums, there is an "EX" version. Is that an expnsion or a massively reduced version? If it's a stand alone, it looks like it could be quite good for the £65 ish it will cost.
Thanks for all the info again MDV. I never got round to mentioning in the other thread, but that song is pretty great. It's making me consider a Ceramic Nailbom or Aftermath for my eventual second BKP set.