Started this challenge, finally.
As of right now, I only have the 1st Gym badge.
Treecko Lv. 15 - Bullet Seed, Growl, Absorb, Quick Attack
Ralts Lv. 11 - Confusion, Growl, Double Team
Nincada Lv. 6 - HM for Cut and Flash
EDIT (07/29): Three Gym badges! Now in Route 112.
Grovyle Lv. 21
Kirlia Lv. 20
Makuhita Lv. 20
Tentacool Lv. 20
Numel Lv. 12
Nincada Lv. 6 - HM for Cut, Flash, and Rock Smash