Define "cheap"
Rack mount as a factory feature means a pro unit. They start at about $400 new for Tascam's cheapest. Most are $5-600.
Consumer units start around $200, need "music" CD-R blanks and you'd have to jerry-rig them into a rack.
Ones to avoid: I've heard horror stories about the older Philips units that are all over eBay. I owned a JVC unit for all of a weekend before I sent it back as it didn't work properly.