I have no experience trading with a forex prop shop. I have been in an operations capacity for a major Wall Street firm that handles clearing for several equity prop firms. The term "bucket shop" comes to mind.
On the equity side there a few decent players. If you have questions about equity firms go here:
Elite Trader - The #1 Site for Active Traders (Don Bright is an experienced vet from the Philly exchange. He may be able to direct you.)
Also, this is not an advert for the above site or a plug for any individual mentioned. We must all do our own research and due diligence homework. Hope this is helpful.