So my electric contractor wants to bring my power in via a 80 schedule conduit to the outside of my SIP, fully insulated, unconditioned garage. The meter would be on the outside and the 200 AMP breaker box would mounted inside the garage where the other circuits would go into my ranch style house. I'm not sure if he wants to do this on the shared interior wall or the inside of the far wall where the meter will be mounted outside. In order to have the box flush mounted I'd have to remove the foam and box the breaker box in. My thinking is this kind of defeats the purpose of my SIP setup to begin with. I guess it wouldn't be as bad on the shared firewall side, but I'm not sure if the code guy will like it much. Should I just demand that they do what I originally wanted and mount the meter on the outside and run the wire through the trusses and down through one of the interior walls in the house into the basement? It seems like much more sense to do it this way since my heat pump and HRV are going to be located in the basement along with the inverters for my solar setup. Or maybe I'm missing something???

First, don't try to flush mount your panel in a SIPS wall. If you have to mount the panel on the SIPS wall, surface mount it and built a 2x4 wall around it, much easier for everyone concerned, and it doesn't take up that much space out of your garage.
Second, from your description of your setup, why would they even consider not putting the panel in the basement, which is where it really needs to be.

In case you're not aware of it, if you do this you will need to have a service disconnect at the meter, or on the wall directly opposite the meter. You can then put the breaker panel wherever you want, with some limits such as not in bathrooms. Service disconnects are pricey. I ran about 100' additional service cable inside 3" conduit outside of the house for what it would have cost to put a service disconnect at the meter and run 70' of  125 amp and 30' of 70 amp service entrance cable inside the house. The two options I was looking at was the meter with disconnect only 30' from the street side junction box with one each 70 and 125 amp panels in the house, or 130' with 200 amp panel with 200 amp main breaker in the garage feeding a 70 amp sub panel in the utility room. The 130' option was the cheaper.

Cost is why the electrician wants to put the breaker panel directly opposite the meter. You can run a lot of #12 wire inside the house for what it will cost to separate the meter and breaker panel by more than 5 to 10 feet. 200 amp main breakers which are purchased separately from a 200 amp breaker panel are very pricey!

Your least costly approach may very well be to put the main breaker panel on the outside wall and run a single larger cable, such as 70 or 100 amp, to a sub panel in the basement. The sub panel would serve your heating equipment and other loads in that area of the house. However, breakers above 70 amp get pricey. You can buy a lot of wire for the price of a 100 amp breaker!

He should be able to use schedule 40 conduit for the underground portion of the run. Schedule 80 is only required where the conduit makes the turn below ground up to the meter. That is if your power company doesn't have different rules from the NEC.

I did this in the garage of my ICF house w/ attached ICF garage. Great way to do it!