"is it possible to use standard aero bars on a road bike and get a good position? "

Unless you've got a really long torso, most people will be stretched out too much. The slam position works for some people. As I understand it, jam your seat right back on your railings and dop your seat height an inch or so below normal. Use short aerobars such as Profile Jammer GT's, etc. It's described in detail on John Cobb's site. I raced my first two years this way. It went well but in my case my hamstrings always felt tight going into the run. Some others don't seem so bothered.

Another road bike option is the "multi-sport" position by shifting the seat forward to an approx 75-76 degree effective seat angle. This works best it seems with compact frame designs such as the Cervelo Soloist, Giant TCR, etc. Use aerobars that are one size smaller than normal ie, for example, small Syntace C2's if you would normally use medium on a tri bike.