I agree SCTO is the best option, I have a 2 Kilo gas drum roaster for my customers I get the scraps of what is left over, the SCTO is what I use for my personal roasting 90 % of the time, with a little practice you can put out a nice roast. These can be built for around $100 bucks, their are many people on this site that use this type of roasters, Peter is considered the guru in my opinion. Milo turned me on to this system about 4 or 5 years ago and that started my obsession, between family friends and neighbors. Had to up my game and purchased a 2 kilo drum roaster to keep up with over a 100 lbs a month of roasting.