Why specifically do you say to avoid 4 strokes? When I got my skeeter, I had them pull off the Vmax and install the 4 stroke (not the SHO). I bought it for the quietness, much better fuel economy, no constant cost of 2 stroke oil and long term durability. Like the OP, this is my retirement boat and I was much more concerned with cost of operation and durability than I was with anything else, and I've been very happy with my decision. 450+ hours on it now and it runs as good as the day I bought it.
The Yamaha website says Rainbow Marine, Cableas and Roger Outdoor Sports are all Yamaha dealers, so I'd guess/hope one of them would have a good service dept. I've not had to get any Yamaha service since Waymack has closed, so I don't know for sure. I guess I'd hit Rainbow first, though, if I needed service on something I couldn't handle.