Why did thay suspend you? That would be the first step and to correct that problem - unless you were selling something that was listed in their AUP?

And then of course it depends on where you are located as well for a merchant account or another Internet Payment Service Provider (IPSP).

You will definitely need to address your "security issues" before establishing another merchant account as whomever you go with will most likely have the same issues with your account.

i use 2checkout and it seems alright but i would rather be using a nochex merchant account

I agree with stymiee you need to address your "security issues", however you can check different payment processors those who can meet your requirement, if you are looking alternate solution in UK, I think this tool might be helpful to you; electronic-payments.co.uk/product_data.jsp