always wondered what the ground attack version would have looked like
Several variants were proposed and investigated but not produced, including reconnaissance versions, a fighter bomber version with underwing panniers for bombs, and a supersonic variant with area-ruled fuselage, thinner wings, and a new tail. The "thin-wing Javelin" would have been capable of about Mach 1.6, with a higher ceiling than contemporary US designs. Initial work started with fitting a thinner-section wing to a Javelin fuselage but as the project developed the changes became so great that it would effectively have been a different aircraft albeit having an outward resemblance to the Javelin. The final incarnation of the thin-wing Javelin just before cancellation was a large aircraft carrying two Red Dean all-aspect missiles as a possible contender for Operational Requirement F.155.
http://en.wikipedia.org/wiki/Gloster_Javelin