I don’t have on to sell you, but this is not the place to look for a maggie. Look on Otn (observedtrials.net) 80% of trials bikes have maggies. You can often find them for 40-50 bucks each.
Edit: scratch the first part about me not having a brake to sell you, Though i am using it at the moment on a bike, i may be getting a new one soon and would sell mine for like 40-50 bucks. I’ll get back to you on that, in the meanwhile, check otn.
You’ll also need a set of 4-post brake adapters if you buy the set on eBay. My new KH29 came with a set of these (I don’t remember them being included with my KH24, though; they were in with the pedals this time). UDC sells these for something like $10 plus shipping.