What Controller for Mirroring (simple RAID 1 Mirroring), Software Issues?

I want to mirror two drives. I can get two identical drives to use.

If possible with Linux, what controller/chipset what be best to do this with using SimplyMEPIS 6.5 -- hopefully something I can grab from a vendor like http://www.newegg.com

SATA would be preferred.

How big of a performance hit?

With Netware (at least 2.xx, 3.xx), I used to see performance increases when mirroring at times (using the software mirroring built into Netware), thanks to split reads between drives and more read compared to write activity.

But, with most Operating Systems, the opposite seems to be true (performance hit when mirroring). So, I'd prefer a hardware solution that works as well as possible with LInux.

Suggestions?