I started my build by using loads of masking tape. Physically mark out in tape how you want it to look, when done sit back and think about your design an see if it's practical and plausible.
I would mount it on a trailer just as you haveit in your truck and only cut the top 3/4 of the way back allowing for a second shelf to be mounte up high.
Have a look here for ideas. http://carolinacookers.com/pigcookers.htm
I would post photos but this iPad sucks an I'm not on tapatalk.
Slappin that bass like some delerious funky preist!!!
UDS, Half Pint (Mini UDS), Weber, ProQ 20, Kegrilla
*250 gallon cooker- 'The Meat Beast!!'*
British BBQ Championships
Grand Champion 2008
British BBQ Society - Southern Championship
Grand Champions 2009