I've actually had zero problems with Alex rims (except one that taco'd after I went straight into a stop sign), but the CR18s with Alivio hubs sound like a good deal, even if you need to do a little work on them.
Also, if you end up getting 135mm spaced hubs, you probably don't need to actually cold set the frame or anything like that...it's pretty easy to flex the dropouts apart by 5mm.
It seems like it's a choice between an $80 wheelset you might have to work on versus a $120 wheelset that you built yourself and the strength of which you are confident in.