Why do you need a tailored suit? Are you an odd size? I was, at my biggest a 50 jacket, 33 waist. I would just buy a 50 Athletic, and get the pants altered.
Try brooks brothers, you can get a nice custom cut, made to order suit for about $600. If you want to wear that ultra conservative, hasn't changed in 100 years suit. Just plan on looking like you stole it from grandpa.
I would go to Nordstorm, or Saks. At least there you will get something that won't make you look like a senator. Unless, of course, that is what you are looking for.