Nice Sonex! You are already truing out at 175 mph at 4000msl and 2788 rpm. That is about all the speed can get in a 3300 Sonex/Camit/Jab unless you get higher.
My first Waiex was a fast one with the 3300 Jab. WFO it would get to 186 mph at about 3000 feet but it was burning more fuel than I wanted it to and pushing the revs higher than was prudent for a long cross country. I always planned my flights for 2800 rpm,161 mph, burning 5.9 gph at about 8000 ft.
Mine was watertight just by using "D" shaped adhesive backed weather stripping something like this:
https://www.homedepot.com/p/M-D-Buildin ... &gclsrc=dseveryplace the canopy meets the windscreen and airframe. On the rear bulkhead, I did not attach the weatherstrip to the canopy. I attached the weatherstripping to the rear bulkhead so the canopy would come down and seal against it. It made a huge difference in keeping the water and wind noise out.
Look at a bunch of different weatherstrips. This one needs to be small, soft, and very flexible. It gets changed every few years.
I had the same trio A/P in my first Waiex and it performed great. Heated seats are the way to go. I did put a heat muff on my second Waiex and it worked well for me. Others have not had the same result. Best of luck with your new Sonex.