My understanding is that both will create more soot (because on a real basic level they shove more fuel in) thus it will clog the DPF sooner - so in both cases a DPF removal is advised.
There are various people on here running both of them with varying results from what I have read - even some running the CR engine and Tuning box with DPF in place.
My personal opinion is that the tuning box modifies the map signal from the ECU so can only really do a really basic power increase modification where as the remap can finely tune the Map to be correct at all times. It also helps that a lot of companies offer both a DPF removal and Remap in one bundle that isnt much more expensive than just having one of them done...
EDIT:
Sorry, I made the assumption you have a Diesel... is it a Diesel you want remapping?