I agree with the other posters. Doing or learning how to do as much work on the car yourself is the best option. However, I can relate to your situation. So assuming (dangerous word) your mechanic is as good with turbo Buicks as you have been led to believe, I’d sit tight and wait as much as that would suck. If he’s as good as advertised I would expect to have to wait. My personal experience with good older mechanics is they may not necessarily do well with the whole communication thing but when you want shit done right, that’s where they shine. Not saying that’s the case here, just stating my experiences. I would still make that 45min drive to see what’s up though but that’s just me.
The longer term goal would be to dig in and do the simple stuff on your own (like installing a scanmaster and chip) and branch out from there as your confidence grows. Sounds like your car sat for years. Unless you’re very lucky it’s going to need more attention even after the head gaskets are fixed. Learning to tackle the simple stuff on your own is gratifying in itself and likely to keep your interest in the car longer than if you had to farm out the work every time it needed something done. Not to mention how proud your dad would be
My worry would be the complexity of your car. Seems like it may be well modified and have some one-off stuff on it that many might not be familiar with and that could impact how much useful help you get from this board. I’d try and simplify if possible and maybe take some of that stuff out unless you understand how they work. Just my useless 2 cents… Good luck either way.