Convert an old road frame (using spare parts like crank, stem, seatpost, etc) look for something with 130mm rear drop outs, its a common hub size thats easy to find/space to. The horizontal drops will allow you to slide your wheel out while keeping your fenders bolted on. Which you cant do on a track frame with full fenders. You also have clearance up to 27"x 1 1/4th or 700cx38c cx tires of your choice. All of these sizes are common and easy to source out parts for. cheapest way to build something "nice"/reliable.