SIL RAID - sparate RAIDs possible?

I have a RAID0 setup of 2 maxtor 200GB '10s', these are now rare (or at least more difficult to buy new) so if I wanted another pair of drives they wouldn't be the 6B200M0 model but either a later variant or even a different make (such as WD's) and possibly, or rather probably 250GB or 300GB instead of 200GB.

This is on the SIL3114 RAID controller on an ASUS A8N SLi Premium (the NVRaid is full of standard drives).

a) Could I have 2 different RAID sets on the SIL3114 controller?
b) Could I use all 4 drives as a single RAID? (assume another pair of same drives added)
c) Could I use a bigger pair of drives or different make of drives in either the above situations?

Thanks

Is there anyone who knows RAID and RAID controllers?

With the SIL 3114 on the SLi board, I have found out that you can't connects SATA drives as just legacy drives - it has to be raided. It's is currently RAID0,

What happens if I add another drives, can I add a single one, does it have to be a pair, do they have to be same model, or same size etc>

Anyone?

Pwwwweeeeeaaase

afaik it is possible to mix n match drive's made by different manufactures but for sizes of drives it would be best to stick to the same size, as if you buy say 2x300GB drives and add then to your current 2x200GB then you lose out on 100GB from each of the 300GB drives ?
also i think if you wanted you could just put the 1 extra drive onto the Raid0 setup you have at the minute.