I got this made (puts drain, nipples, etc. where you want) by a guy on ebay for like $25.00. If you need his info let me know, its very thick and well made. The cap is great as well.
DSC_0035 by
9krpmrx8, on Flickr
I also had this one that I bought at Advanced Autoparts for $10.00. The cap sucks a bit but the reservoir is good. I just got a four point strut bar so I have to rework my setup a bit now.
sohn by
9krpmrx8, on Flickr