Mine liked JSB exacts 8.44 4.53s. Some like 4.52s. I'd start with those two or the air arms equivalent.
Improvements wise, I'd try zeroing without the original stripper, then try with it to compare. Consider a replacement item, mine had a crap original item as it was not concentric with the barrel (I'm not suggesting they're all bad but mine was).
Hamster another consideration.
Have trigger polished and lightened. Mine set as finely as I could get it still caused me to torque twist the gun slightly upon pulling the trigger. It was fine after the work
MPR trigger blade if you don't like the button or even try spinning it round
Good gun, practise, practise and more practise and you'll see improvements anyway
Steyr LG110 HFT 2014, Warren Edwards grip set, MTC Viper Connect 3-12x32 SBC
Air Arms TX200 mk3, walnut stock, Delta Optics 4-14 HFT