This last year I've had great luck with wearing the 'super tight' shorts, whose official name I'm not sure off, but available in running stores. Then, wear a pair of 'normal' shorts over them.
The tight shorts serve as the undergarment (tho you could wear them solo) and really really cut down on the chafing. I don't wear underwear anymore, though for long runs still put on some bodyglide.
I also generally can't stand my VFFs for pavement running, especially not long distance, though they've served me well on longer trail runs.
Congrats and cheers!
John