For more information than you ever wanted to know, check out the forums at brianenos.com or glocktalk.com
I used a Glock 22 in USPSA Limited for a couple years. I added a 3.5# connector (which I believe your G35 already has) and some MMC sights as even after some filing I just didn't like the stock sights. I never used a mag well per se but added a Seattle slug which adds a bit of weight and extends downward a bit at the rear of the mag well. For pure competition use, a mag well funnel is probably a better idea.
I used three different mag extensions all of which worked well. I forget the names of the first two, but settled on Arredondo because it was easier to disassemble the mags. All were 20+1 capacity.
I heard all the stories about Glock kabooms and it was my intention to use lead bullets due to cost, so I got a Bar-Sto barrel. Accuracy improved by a minor amount. The chamber is noticeably tighter and fired brass does not swell as much as with the factory barrel. This was my first .40 so I used factory ammo through the stock barrel until my brass supply built up.
During the time I used it for matches, I put ~30,000 rounds through it with no complaints. I later replaced it with a Para-Ordnance P-16 Ltd for match use. I still have the Glock which with the addition of night sights has been upgraded to HD use.
