One way to do it fairly cheap can be to get lucky and find the right kind of "for parts or not working" rack unit on eBay or similar. This will often give you connectors and even some power stuff as well, if it all tests OK. If your controls are wired off-board you might even be able to reuse the existing front panel. Cheap thin wood veneer and a layer of stain plus varnish is a very cheap way to cover an existing design, then label it up using whatever you have to hand (waterslide transfers, printed vinyl stickers, handwritten, etc).
I used this approach for a stereo Bax EQ, which I built into the enclosure of an old knackered Aphex unit. I was even able to reuse the entire power supply! Cost me £30. It's the wood-faced one in the middle of this rack:
I'd avoid Behringer for this sort of thing by the way, their enclosures are a bit tricky to rework.
Another way is to get a blank enclosure and drill it out yourself, of course. Probably wouldn't cost a lot more, if you've got access to the tools.