I was looking into custom slide serrations in the past (different gun) and prices ranged from $75-150. Then add the cost for rounding off the edges, plus refinishing the slide. Total cost might be more than it's worth in the long run.
Consider getting the gen. 2 model and putting in a lighter recoil spring + stainless steel recoil spring rod from Cajun Gun Works -- that'll help a great deal from day 1. A few hundred dryfires and the DA trigger will smooth out as well, or you could do some area-specific polishing of a few internal parts. If you sell your P-07 Duty, your out of pocket cost will be less, and you'll have the new trigger & swappable backstraps, dehorned slide & frame, front slide serrrations, and metal sights. Just my 2 cents.