Here are some ideas for Target Indicators (TIs), for your RAF Night Bombing Raids:
http://leadadventureforum.com/index.php?topic=104733.0For 1/600th scale, and perhaps even 1/300th scale, I think colored, metallic glitter might be best, but metallic colored "Tinsel Stems", aka Pipe Cleaners should work nicely for use with larger aircraft, like 1/144th scale models.
Of course, if you want, you can even go with colored lights too. The battery-powered, small LEDs and micro-lights look to be perfect for this, and would look stunning, no doubt, if you can dim the lights in the gaming room you're using.