Well first bit of advice would be to get the details for your inspection bcus you're gonna hate yourself if you do the work and gotta reverse it annually. But honestly for your application I'd advise a 5 inch straight pipe, whether you want a muffler or not is up to you. But like you said, the DPF and DOC have to go. Then I'd get with Korry Willis or ATP and buy some EFI tunes and a DSP5 switch. That gives you 5 tunes to play with. They'll make you a good tow tune for your loads and some very fun trans safe tunes. The EGR is definitely good to get rid of. Do a full delete though, don't just put a plate in if you really wanna do it. Also I'd get a downpipe, the stock ones are crap, literally. 2.5 inch pipe pinched down to about 1.75 in the middle. Also get a PCV reroute kit, your intercooler will thank you. That's about $1300 in parts, if you need to trim that down to fit your budget then you can.