The advice I remember is to get a NEC chipset for USB and a TI chipset for FireWire. However, I don't remember/know any of the specific info you asked about regarding causes.
We've had a Adaptec brand USB 2 card with NEC chipset in an MDD here for several years and I have not noticed any sleep specific issues. On rare occasions the keyboard/mouse connected to the built-in USB has failed to work after sleep until it's unplugged and moved to the other built-in port, but I have no reason to suspect the USB card and the problem is very rare.
I just bought a couple of USB card's with NEC chipset from Newegg for under $10 each. They're no-name ship from China card's. We'll see...
We've had a Adaptec brand USB 2 card with NEC chipset in an MDD here for several years and I have not noticed any sleep specific issues. On rare occasions the keyboard/mouse connected to the built-in USB has failed to work after sleep until it's unplugged and moved to the other built-in port, but I have no reason to suspect the USB card and the problem is very rare.
I just bought a couple of USB card's with NEC chipset from Newegg for under $10 each. They're no-name ship from China card's. We'll see...