High rail engines on scale trax or realtrax

They will all run on any of it. I personally do not like the look of RealTrax, but it has been around for years. ScaleTrax looks very nice and has a low profile. Both work; RealTrax may be more available.

My layout is painted GarGraves/Curtis/Ross, as info. This seems to be the friendliest family. ROW track is also compatible. ROW and Curtis are no longer around.

Can I attach scale trax to the railking bridges and how bout the older lionel lift bridges that raise vertically 

You can use it with most anything, may take some fiddling though with different ones.

FYI though, get it now as supplies will be limited due to MTH shutting down next year.

It's a great track system, I love mine, sad to see it go.

The Lionel lift bridge of 2002/2003 has tubular 031 profile rail molded right into the decking which is virtually impossible to remove. You would be better off to transition at the ends of the bridge to your scaletrax/realtrax.

Rod

You can make RealTrax look pretty good, but takes some work. My whole layout is RealTrax, but if I could do it again, I would use ScaleTrax. Also, the RealTrax is noisy.