This is a tough question to answer because the answer is likely to be larger and far more expensive machines. We use SMT lines that are over 50 feet long with

This is a tough question to answer because the answer is likely to be larger and far more expensive machines. We use SMT lines that are over 50 feet long with pick and place at one end and AOI (Automated Optical Inspection) and x-ray inspection at the other end. That said, back when I was still bootstrapping my business in the garage I reflowed SMT boards with everything from toaster ovens to hot plates. I have to say that my favorite budget reflow tool back then was a hot plate with a really thick top. There are some that have a metal cover box that will make a little oven-like environment. None of these are 100% reliable, of course, and a lot depends on the nature of the board, size, type and mass of components, etc. What you do get is precise temperature set points. I'll see if I can ask our manufacturing engineers tomorrow and see if there is such a thing as a cheap lab-class reflow oven that does a decent job. It isn't going to be $200, I can tell you that much.