My advice would be to start with the skillet technique - see the Sparkfun tutorial. For anything other than simple designs, I highly recommend Ryan O’Hara’s $25 Kapton solder paste stencils.
If you really want a reflow oven, I suggest one of the cheap (a few hundred $ on Ebay) Chinese units. Check the forums to see which units people recommend. I have one and it works quite well. I certainly wouldn’t spend thousands for what you’re doing.