The idea sounds very cool; however, are you aware that community servers (pubs that are not valve servers) are kind of dead in tf2 right now and most people won't find your servers through quickplay? You will need a lot of advertising to let people know that your thing exists. And unless your prizes are so dank that people will actually commit to pubs to get them, you'll have to keep up that advertising so you always have new people coming in when the others get bored/decide to just click quickplay.
Also, you might have to worry about moderating your servers against cheaters at some point because even though lmaobox is being detected now, new hacks can always appear and people will use them in pubs undisturbed for 10 years before valve finds out.