Hi,
I am currently in the UK on a 18month Tmobile contract that ends in March so I can't upgrade

I am going to be staying in the US for a 3 month period and would obviously like to use a phone.
I can get my hands on a brand new Unlocked BB Curve for £260 ($527). So I can put different sims in etc but my plan was just to buy a Pay as you Go sim so I don't have to use my UK tmobile plan and get hit with the costs. Now I have been told that if I go pay as you go I won't be able to get my emails etc. I would also like to get access to the internet just for maps and things. So what would you knowledable people suggest? Get a pay as you go and just accept I won't have any access to the internet or emails, or is there some other plan which would be better.
Also can you get BB Curves that are Unlocked and not on any network in the US? If so how much are these in the US