[CQ-Contest] Question about USB to Serial (DB9) port adapters

[Ray]

I am new to this list and am looking for information about USB to Serial
port adapters. I am looking for a 4 port Serial adapter with USB input to
install and setup on a Windows XP computer for computer logging (DX4WIN) and
contest (N1MM) programs. 
 
A friend of mine uses a Keyspan 4 port unit and has no problems. I have
found a number of other brands but am wondering if they will work without
problems. One is #5370 (no MFG listed), another is a USB Gear 4X32, and yet
another is a Y&L (no other info). Each of these units are a lot less
expensive than the Keyspan. 
 
Can anyone recommend any of the above units? Or do you know of serial
adapters that are easy to setup and would recommend?
 
Tnx,
 
Ray, 
N6VR