Credit Card merchant account from all directions

I run a small online company and we take credit cards. In the last month, a few people have offered (mostly thru automated marketing systems) to help me take payment online. It's an impressive list:

My Bank - Bank of America. Also other banks have offered me services.
Paypal - They say they can be my one stop shop. Of course, they can't do subaccounts or categories and, if there's a customer dispute, they'll freeze all my cash until it's resolved.
Quickbooks - Heh, even my accounting software is marketing to me. It's good software too.
My hosting company - I host sites in several different places. Several have sent me marketing emails offering to clear my credit cards for me.
Google - Google has Google Checkout: Process transactions for free when you advertise with Google. Google Checkout is a fast, convenient checkout process that brings you more customers and allows them to buy from you with a single login – and you can process their orders and charge their credit or debit cards for free.
A number of independent sales agents. I guess they would count as ISAs, independent sales agents.
Several friends of friends. I just bought and sold a house and my real estate agent (my new best friend), introduced me to someone in his local business network who sells credit card merchant services. My daughter's friend's mother now works for a large bank as part of a sales team. Her expertise is payroll services but there's a merchant services salesperson as part of the team. In fact, I was at the dentist today and in her family is a little brother who sells merchant services to doctors...

I guess my point is that there is probably a business situation in which you would want to work with each of these different types of approaches. This blog, with it's articles and forums, once I get it fully going, will be a special source of information on how to compare these different choices.