I'd recommend Merchant Warehouse, or Flagship Merchant Services. I personally use Flagship, so far they have been great and have low prices. A good friend of mine used Merchant Warehouse and had good results.
Authorize.net is another to consider. Plus from the sound of it you'll need a physical terminal to process the cards, this is something else to consider.
Your best be is to call these companies, tell them what you want to do, and above all (from my perspective) be up front. If you get a little "sketchy" about your business while you are trying to get approved, they will turn you away, or flag you as "high risk". With respects to account freezes, it varies from company to company. That is a tough one to pin point. Hope this helps....