here is a possible solution:

go to ebay for PERC5i or PERC6i

both cards do the RAID level(s) u want.
the PERC6i even does RAID6
both cards are a lil old, but will still be far better than onboard intel in RAID5 (in fact, the PERC5i has same XOR as the areca 1210)
both cards have cache - the 6i has 256MB, the 5i has a upgradable RAM DIMM, so u can choose between 256 or 512MB cache!
& both cards are under USD$200 on ebay