You can also try Indochino.com, they do have 3 pc options. I recently order a suit from both Indochino and TaT. They Indochino one shipped in 6days I should be receiving it soon. You also get $75 tailoring credit, so you can do a final fitting and adjustments with a local tailor. Otherwise your best bet is to find a local MTM shop, but usually that will run you more $$$.
Most "affordable" MTM programs are from Asian sources and they only take online orders. Those who offer fittings in NYC, although still made in the Far East, are more expensive. A three piece suit will probably push the price up to $1000.