Hi Vikki,
There used to be an outfit at Swansea which flew Vampires but I am unsure if they are still around.
I'll try and dig out a school in California which will train you to solo standard in a jet, but you need an FAA IR before they'll take you on.
Kemble and Delta Jets is probably the better option... I believe they train you to fly Hunters and if you buy a share in one you'd be able to take it out... solo!!!!
Now that must be the ultimate PPL Jet...
...with the exception of a Citation Jet which are Single Pilot Approved but you'd still need a PPL/IR at least for one of those.
RichyRich: Not all the regionals fly jets - Air Wales only has ATR42 Turboprops. Oh then again thats the national airline for Wales so maybe that doesn't count as a regional.
Best wishes,
Charlie Zulu.