Doing tech inspection for the HMSA these past few years has caused me to re-evaluate a bit here. While i'm all for a properly baffled can, particularly on high specific output forced induction applications, it would blow your mind how many of these rich schmucks with priceless historic race cars use modified aluminum water bottles, like the kind you'd buy in the Outdoor section at Walmart, or perhaps something even more ghetto.
Granted, this is mostly on normally aspirated stuff that's decades old, and again i'm all for a properly baffled can in your case, but my point is that at the end of the day it just needs to a) not leak b) be secure c) be in a location that is easy to drain and check level and d) depending on the engine and catch can configuration, be properly baffled. I feel like you are on the right track here and could probably make your own fairly easily and economically.