Suit separates are individual coats and pants from whatever manufacturer. Suits are cut from the same bolt of cloth and made to be worn together. Zero difference in shade/dye job. You can get pretty close to the same color with suit separates, and sure, most people can't tell unless they're really looking, but it's a lot worse to try to match two very similar colors and fail than matching complementary contrasting colors. Maybe I went overboard saying that suit separates aren't worth looking at, they certainly have their place and can look great. I'm just of the opinion that if you're shelling out money for this kind of wardrobe, a classic, true suit will always have a place in your closet and you can worry about separates later.
Also, any decent tailor should have no problem fitting you into an actual suit unless you're built like the Stay Puft marshmallow man. The Men's Wearhouse people may have just not wanted the job.
Since you're a noob, and if you'd be comfortable doing this, I recommend going to a local high-end shop in your area and tell them what you're looking for and when you tell them your lower-than-they-can-accomodate price range, ask for suggestions and tell them you'll be back when you're pulling in a physician salary. Just be upfront about not being able to afford their stuff though (unless you can).
