The ones I have pass all the handshake signals but I don't think either is still sold. One was a multi-port hub I got several years ago (the company was absorbed by Intel) and one is an eval unit from FTDI using their first chipset.

The chips made by FTDI and by SiliconLabs handle all handshake lines but adapter manufacturers may or may not implement them.

I would suggest getting one of the breakout boards from Spark Fun, either the FTDI or SiliconLabs boards.