.

Personally I'd try for Regions because I think it would give me a heads up on Bham and Atlanta. Don't know much about RJ though.

Also, I'm not sure what you're your interests are, but Ayco has an Atlanta office if personal wealth management appeals to you. I know some people who interviewed with them and thought it was really interesting. Might be a little too detached from banking for you, just a thought.

I live near Charlotte, NC and this area is known for banking Wachovia and Bank of America. You might want to check them out.

I live in Tampa Bay, and as the OP already stated, Raymond James' HQ is here. They have a HUGE presence in the community, and I have known people who worked there and they enjoyed it. It is known in the Bay Area as one of the better companies to work for.

I don't know about internships, but I do know that SunTrust Bank has several large centers in most of the major Florida cities, Tampa, Orlando, Jacksonville, and Ft. Lauderdale.

former banker
 

Banking is its own animal--the best way to get ahead is to leave and come back to the position that you wanted, so start somewhere (any internship in Wealth Mgt should be noted).
It doesn't really matter as long as it's a regional or super-regional bank, even if the one you are with doesn't have a presence in the city/area where you'd like to end up. If this is a confirmed internship, stick with it. They are definitely not a dime a dozen, so don't throw it away! Other opportunities will come from it, and you might find that you interview later with Sun, Regions, BofA, Wachovia, other, larger institutions may offer you a better position because you worked elsewhere and have exposure to various products (account types) and computer systems.
Raymond James is a brokerage house, and a very respected one at that. Same situation: just because you are with one company today doesn't mean that your experience won't buy you a better salary later.
Brokerage firms will offer you more chance to actually use your knowledge outside of the finance realm through the research departments. Banks don't have a lot of research opportunities--those are typically purchased from a vendor (other brokerage house, proprietary research firm, etc).
Short version: hang on to the internship unless something much more glamorous comes along. M&I is a good, solid bank (manager I used to work for is now one of their local execs in Orlando area & is very happy). It would be recognized in banking and financial circles wherever you land.

Regions is huge. I never heard of the others, but then I've been a stay-in-state gal for a while.
My nephew just got a $50,000 a year job offer from Compass Bank, in their management training program. He has a BS in accounting and has been working for a local accounting firm for three or four months.

Banking in the Southeast
 

On the Mortgage side I believe that they are both predominately portfolio lenders. While balance sheet lending may offer a bit more aggresive pricing the paper is typically a bit more conservative when it comes to underwriting guidelines. Boils down to simple economics. The other issue with portfolio lending, especially in this environment, is that it offers little to no margin when passing the risk into the securities market. Basically, you end up getting clipped when trying to generate cash flows for new lending money.