Crossover Fan Fiction

Hi! I'm Jormy - or Jormandugr, if you prefer, or Sylvia if you want to get boring and truthful.

Essentially, my status is this; I am writing a crossover. It is a Hellblazer/Dark Tower crossover, as the more astute of you may have guessed. *pokes title*
However, there are two small problems:
1) I am incredibly paranoid about my characterisation (especially of Roland) (ironic juxtaposition with icon, y/y?)
and
2) I am a Brit.

The first would be one hell of a lot easier sans the second.
So what I am really after, to be honest, is an American with a decent knowledge of TDT canon, who can check my characterisation and also give me advice on New York slang, geography, shops, jokes... you know, the sort of stuff that's slightly necessary in that context? Preferably to go through spelling and grammar as well, but, well, I can get someone IRL to do that. xD

Oh, and lest I forget, if all goes according to plan, this fic should eventually span everything from about two-thirds of the way through 'The Drawing of the Three' to the end of 'The Dark Tower'. It will be long. There will be spoilers. It will take months to write, let alone beta.

However, I have been searching for a beta for it for whole days, so if you'll do it, I'll just about love you forever.

Tchuss, alles!

(If I've made any massive and stupid mistakes in this post, rest assured that it's probably because I'm writing it at 3AM. I swear, I can write coherently when I've slept! xD)