I read the title and thought this was going to be a Woodpile thread.
The jury is still out on what works 'best' for a UDS so IMHO I would say start simple and go from there. I started with two 3/4 intakes and one 2'' exhaust and I burn just fine and have plenty of control.
Remember the wonderful thing about a UDS is it's simplicity.
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