Welcome to the site....I personally like the oil tank builds. Gives a guy lots of realestate when you square the front. At least 4 same size shelves. Awesome build when insulated.
Noting wrong with the RF rigs. They are amazing also.
Since it sounds like you are a Fab guy. Maybe think about a small RF and then a FEC style clone ..... coals or pellets.
Just set mine up with a stoker and lovin it to no end.