Irish, it's a real shame that your pc isn't letting you run Arma II I'm really looking forward to this F-22! I have a similar system to you but i'm running a 4890HD and I get the same lag, freezing and crashing it is really frustrating when you know that, with minimal bugs, Arma II could be contender for game of the year in my books.
Anyway I hope you get your problems solved asap!
I'd also like to ask (since you seem to be preetty (no, really really) good at modelling).. do you know of anywhere I can read tutorials? I'm looking to start modelling but whenever I try I always hit a pitfall and something goes wrong and I never manage to finish anything.
I guess this is swaying into the realms of being off-topic.. but I'd LIKE to make modded gear for Arma II so.. yeah..