3-1-3 Machamp Prime
Pokemon Total = 19
4 Professor Oak's New Theory
3 Pokemon Collector
4 Pokemon Communication
3 Junk Arms
4 Rare Candy
Trainer/Supporter Total - 22
19 Fighting Energy
I'd add in another machop and machoke, just to ensure that you can get machamps going throughout the game with pokemon catcher in the format. In fact, you might increase the stage 1 number to 3 in both of your lines if you find that there's a lot of trainer lock in your area. Otherwise, your line of pokemon is very strong and I can't think of any other way to improve it.
I know that with gigalith's shear you want to run a high number of energy to be able to sucessfully attach several for the attack, but you shouldn't need to go any higher than 14-15.
The best addition to help with gigalith's sheer is 4 research record (although it will also help with cheren). That way you can toss anything that's not fighting energy down to the bottom of the deck, increasing the chances of attaching more energy with the attack. I'd max out your collector to ensure a fast start as well as your junk arms. Including at least 2, possibly 3, pokemon catcher will help you target weaker pokemon or 'tech' pokemon. 1 super rod will serve as a little bit of recovery. Finally I'd add in some twins, at least 2, possibly 3, since you'll probably be down on prizes as you get two stage 2 pokemon set up.
I've suggested adding quite a few things, but not haven't mentioned dropping anything. While everything else that you have in the deck is great, obviously there's no room at the moment for all of my suggestions. In addition to reducing the energy count down to 14-15, you can also decrease your machamp line since it's just a secondary attacker (possibly a 3-1-2 line). You can also survive with just 3 communication.
I really like gigalith as an attacker, but it's always been so slow to get running. I'm hoping with the changes to your trainer/supporter line you'll be able to get set up a lot faster. I hope this deck works!