Blacked version of the Russian cockpit with clear glass and lots of little tweaks you may or may not notice.
Installed by the file path:
Saved Games\DCS\Liveries\Cockpit_Su-25\Blacked
Then select this cockpit skin in the Special tab in-game.
The gunsight glass can't be completely clear or you won't be able to see the crosshair. I had to darken it a little.
To get rid of the reflections you should also install this mod made by Sérvalpilot:
https://www.digitalcombatsimulator.com/en/files/3317526/
Shadows will still cast on the cockpit glass, playing with shadows off and the mod above will give you 100% clear canopy glass.