As a hairstylist, I have never been "the Mom" with regards to a lo's first haircut...in fact in my experience, many toddlers do just great once Mom "has to go potty" and leaves us alone for a few minutes! LOL! Dd has not had her haircut yet, which I can't believe!
Try the high-chair while he is involved in a really yummy snack or stickers or paint. Trim the area that is bothering you the most first, like the bangs or around his ears. That way if that's all you get to, at least there's a big improvement!
I have, in the past, trimmed a lo's hair in the parking lot of the salon while baby slept in a carseat...car running. Just a trim around the front, turn the little head, trim around the ears, and done!
Keeping their hands and minds occupied is key. If you wish to try something new like a lollipop, then why not! They make organic ones! The high chair is the best place...then they can't run away, but it is critical that they have something really fun to engross them. If he's spirited, I'd vote to put the high chair in front of the tv, and give him a food he loves and rarely gets to have.
Also, ears fold down, so don't be afriad to fold his ear forward to cut around and behind it!
My water bottle has entertained many a lo, too! I would let them squirt my comb, then I'd comb thier hair with it, and then say "I need another squirt!" Maybe rty just that one night...no cutting, just the water and the combing...then again in a few days, then try cutting it on the third try.
HTH!