Go regional
Well, having come from a night cargo background, here is my .02 (and probably worth less than that).
Both avenues offer their pros and cons, so here are some from the cargo perspective.
Pros:
Good instrument skills;
Building PIC time and associated decision making skills (when applicable);
Lots of flight time quickly;
Ability to deal with all kinds of weather (because you are in it all the time);
Some cargo operators have a good rep with some fractionals;
Cons:
Don't have as much of a chance to develop the "customer service" mentality;
You may develop some bad habits that you will HAVE to break;
Don't have as much CRM and crew experience (depends on the operator);
Usually no glass cockpit/FMS experience;
I learned a lot by flying night freight and wouldn't trade it for anything. Something else to consider: In my interview at Netjets, they asked what kind of customer service experience I brought to them from my cargo job . . . . would be alot easier to answer from a regional pilot perspective.
Having said all of this, I would take the first good job offer I received either from a cargo op, or a regional.
Good Luck!
NightCargo