I actually have a few 2.5"/3.5" drive enclosures with Cypress, Alcor Micro, Genesys(not Genesis), Myson Century and new ones with Oxford that I haven't tested yet, but since I'm using different HDDs & benchmarks our numbers won't be directly comparable. Unfortunately I don't know which drive enclosures use which bridge chips, but I do know that most that use Oxford chips aren't cheap. I think there might be some cheap ones with NEC chips.
btw what are your system specs for the bench rig?