Nice build, however I would like to give you a word of caution regarding the changing out the 30 amp breaker with a 50. That 30 amp was there to protect a 30 amp circuit(depending on the type of wire), which is probably #10 wire. A 50 amp breaker will allow at least 50 amps to flow through that wire which is too much and will, over time cause the wire to break down and or melt before tripping. Just a word of caution to avoid "killing your buzz" while building an awesome cooker. You really should identify (if you haven't already) the size and type of wire that make up that circuit.
After all, we do not want smoke BEFORE you are done.