If you're willing to spend some money up front, look at SS Brewtech. Everything I've gotten from them is simply top notch. Prices are in line with Blichmann, et al, and the design and execution is as good as if not better than anything available.
If you want to start small and cheap, get a reasonable 10 gallon pot (definitely with ball valve for draining) and a good grain bag and do BIAB until you want to upgrade and expand. With a simple set up and a few carboys you can make plenty of very good beer.
I do 10 (actually 11) gallon batches in a 15 gallon 2 vessel set up with a pump plumbed for recirculation both ways. The 15 gallon vessels are absolutely maxed out for the batch size but having electric element boil capability really helps in controlling the initial boil and avoiding boil-overs.
Eventually upgrading to all-stainless fermenting vessels, preferably closed and pressure-rated will be helpful. Temperature control for fermentation is absolutely key so start with that and work backwards.