Welcome to the 1200G club!
Based on advice from the retailer who sold me my 1200G, I’m also using the Shunyata Venom. I happened to have one I could swap out the original one with. Honestly, I can’t say changing the power cord had as much of a noticeable improvement as PC upgrades on my other electronics. I was making other changes at the time so maybe it was too hard to tell.
I use and enjoy Morrow level5 phono cables and feel these were a big improvement over the stock cord.
As to other tweaks, I did try Herbies mat and didn’t like it on the 1200G. That mat was a very nice mat for my prior table which had an acrylic platter. I actually did, just today, order the SL-1200 version of the Funk Firm Achromat. My research suggests that works well with metal platters. We’ll see.
Lastly, I have a DIY maple platform using a Boos Block cutting board and the same ISO blocks that Mapleshade sells. My supplier however offers bigger blocks at a way lower price than Mapleshade.
Carts are Audio Technica ART9 (preferred) and a Lrya Delos I use sometimes. Head shells are Zupreme from LP Gear. Nice head shells, and azimuth adjustable.