Maxima seat covers wont fit because the foam contour is slightly different in ours. I've been looking to do the same thing for my "08 M35 with climate and bose and so far I've found that M/Q/G-series seat covers are also not interchangeable.
I have changed a control module to fix the heat/cool function and they aren't difficult at all. You could probably find two used ones for $30-80 on eBay and it would take 10min to install.
The best bet I've found for seat covers was a local upholstery shop that quoted around $850 for both front seats. Downsides are that it wouldn't be 100% color matched with the rest of my interior, I'd be without my daily for a week, and this still doesn't solve my non-functional lumbar support so I'm still looking for options. Maybe EdBwoy can compare M37 seat mount spacing to see if they line up with ours and if electric connectors are compatible with an M35. *poke* A direct swap with a newer model would give people another option since finding new or decent condition used seats for "06-'10 is basically non-existent.