If you're submitting a script DO NOT send artwork. You're only wasting the time of the artist involved. (Unless you're Alan Moore and he's Dave Gibbons).
Only pre-established art teams get the opportunity to double pitch.
If you're submitting artwork - I'd stick with characters that already exist in 2000AD - such as Sin Dex, Dredd, Dante or Rogue (and even then, I'd probably stick with Dredd). The idea, I think, is to quickly see if the artist is someone who can draw in a '2000AD house style' (which is a pretty open book, but you can instantly tell when something ISN'T 2000AD art style, usually it's too American)
Hope that clarifies it. Though, having said that, it's only my opinion.
- pj