One of the barrel clamp devices with a rail on it, or (preferably) screw a short section of rail to the handguard. Any 1" scope ring holds a Surefire nicely; the G2/G3 models are a bit over 1" diameter, but it will still work.
Mount it on the left side and you can push the tailcap switch with your left thumb; no need for a tape switch.
Total cost (including a G2) under $100
I picked up a nice barrel clamp light from Dicks sporting for 29 bucks, 3 setting...light, strobe, light lazer...with button switch and pressure switch, but id check the google search shopping might be able to find something a little more cheap! If you try and screw in a small rail make sure you got a good idea off your finger placement and light size but since the parts are cheap I guess no biggy if it takes more then one try! Good luck buddy!
I grabbed a receiver cover for 32 bucks and it had the look through weaver so I could still use my iron sights. I got a good deal on a bsa 1 power scope with laser attached and a pic light for about a bill! Im telling you this cause it was a cheap way to get those three for a semi descent price, that way I could beat her up without worrying to much! I detached the light and put it on my fore upper Side which I got an ati kit so it worked out fine, the kits rails are detachable and set fairly far forward so if want accessories but still like to flat hand,its not a prob, and the ergo of it is real comfy! I like it, check my pics....also I only use my fore grip in cq with my laser when shooting from the hip, anything else I need to aim for I flat hand it!
I'm not much of an AK guy so I may be showing my ignorance here... Can Galil parts be fit on to a traditional AK? If so, this: Micro Galil Handguard with Flashlight Adaptor. might work well. Its a replacement handguard with the light holder built in.