I was looking at some 30-year-old Battletech materials and spotted a very cool "spotter plane", seen here:
Naturally, my first thought was "Yeah, that thing needs the 40K treatment." Don't judge me -- I'm in treatment. So I present to you, the "Gull" scout fighter, armed with two heavy bolters and a high-grade sensor package. Thanks to its long wings, it uses very little fuel and can loiter over the engagement area for hours.