tuning help for 2001 tahoe

Hi all , im from the uk and have a 2001 chevy tahoe ive had the head fail on me on cylinder 2 and now wanting to make some thing of the thruck with a rebuild .

now being from the uk there only a few places that know stuff and dont want to give you any help unless your spending the money with them . so id be really greatfull for any help .

the tahoe is my daily driver it runs a lpg fuel only uses petrol to warm up what would be the best parts to fit like heads and cam along with any other parts i already have a pair of pacesetter long tube headers waiting to be fitted , aslong as the tranny can take it ill fit it lol

i havent got a clue what to buy or where to go so all help would be great

well, not tryin to be a dick, but i would start with the trans; its the weakest link. no use in having more hp if it cant be put down.

ah dont say that i really dont want to go down that road :( as its hard to get parts for the right money over here as import tax is a joke .

I have nothing valid to add to this except a +1 on beefing up the trans.
Oh, and I read this in a British accent in my head:-/