PCIe bus to eSATA or USB

Occasionally I have a need to experiment with PCBs with buses like PCIe. Rather than open my desktop chassis and move things around or remove existing cards, I'd like to insert a PCIe card into an external card cage and communicate with it via USB or eSATA to my desktop.

 

Anyone seen anything like this?

The only external PCIE card cadges i have seen use thunderbolt or some custom interface. USB would be to slow and eSATA wont work.

Thanks!