What to do with my 2011 ram

[cacooke0205]

i have a bone stock 2011 ram with the 6. 7 i would like to delete the dpf and maybe get a tuner. was wondering if i should put the whole exhaust on or just do the dpf delete. was also wondering if it would sound better with a 4 or 5 inch exhaust? any recomemdations on what to get for a tuner?