Advice sought re: small volume e-commerce

Hello all, I am looking for a kick in the right direction.

My company has been running a small-volume online business using Google Checkout, which until recently was free of transaction fees (why we started).

However, for several reasons we would like a more integrated solution - it’s odd to redirect customers to Google’s site, and the amount of information that we can capture at the point of sale is limited- we need a detailed contact form for the service we deliver. (no sniggering, it’s not what you think ;))

I am wondering if anyone has experience with a solution that would be recommended for a situation like this- probably 30-40 transactions a month max up to a future max of 100 or so, each transaction about a thousand dollars, detailed contact information captured at the point of sale, preferably credit card processing taken care of. It would be integrated into a pre-built site.

I understand that Google’s checkout has a detailed API but I’d prefer not to get into that sort of development- I prefer a packaged solution.

Does anyone have any advice for me? Thanks in advance…