I gave up on the cheap and cheerful collated screws a few years back as I had a bulk order from Screwfix, so many of them had filled in heads I ending up chucking 20000 screws out... I get a brand name now (Senco or similar) but look for a good deal online.
For the batts, I recently got a new 2,6ah batt for my DWC - it is much lighter to use overhead and when hanging off my pocket - no problems for battery life either, will do a day.