Luckily the Powermasters generally look realstic.
http://www.tfu.info/subgroup/powermasters.htmThe ones released in the U.S. were:
-Darkwing
-Doubledealer
-Dreadwind
-Getaway
-Joyride
-Optimus Prime
-Slapdash
Overlord also looks really awsome AND somewhat realistic, but I think can fetch a pretty high price.
For Targetmasters, the second wave of "Double Targetmasters" all had realistic alt. modes. Construction vehicles for the Autos, and military for the 'Cons:
http://www.tfu.info/subgroup/targetmasters.htmThe ones you'd probably be interested in:
-Landfill
-Needlenose
-Quake
-Quickmix
-Scoop
-Spinister
There's also Stepper, who was reissue #15 in the old Takara collection series. He's a black with flames repaint of Jazz, and was pretty overproduced. Not sure of his prices, but I don't think he'd be that expensive. He was also released in the Hasbro Commeriative series(last one) as "Ricochet".
Finally, we come to the Headmasters.
http://www.tfu.info/subgroup/headmasters.htmVERY slim pickings here, all Autobots:
Hosehead
Nightbeat
Siren
The Japanese version of Siren(Go Shooter) had a spiffier paint job, and Nightbeat was repaitned into the first female Transformer toy, Minerva. I believe she fetches a pretty penny.
Hope that helps

.