An Electrician friend said I could use #4 copper for the (2)120 volt legs and a conventional
Suspension wire as the nuetral. The overhead span is about 35 feet and the overall run
From panel to panel is about 70 feet.The supply outlet said to use #2 copper.
Also, what type wire for sunlight resistance

Part one: NEC 2008, requires a four wire feed to a sub-panel. If you are onlly going to provide power to one circuit or to a multiwire circuit you should be fine, but if you ever have to take it to a 120/240 feed, all of the work you've just done will have to come out.

Part 2, it's not the voltage that is important, it's the required amperage. I realize you are wanting to drop 100 amps to the garage, but I don't think that that is what you actually need. What do you plan to use (electrically speaking) in the garage? Most of the garages that I've seen recently don't draw more than 60 amps.

There is a sticky at the top of this forum that can link you to the NFPA site to read the Code Book online.

A question... is there such a thing as a 4 wire "suspension wire" I haven't seen but it could solve some installation problems where overhead is preferred or underground is nearly impossible.

You need to upgrade your service to a two hundred amp

A question....is there such a thing as a 4 wire "suspension wire" I haven't seen but it could solve some installation problems where overhead is preferred or underground is nearly impossible.

Yes you can get SE wire from the electrical supply to run overhead

you need to upgrade your service to a two hundred ampConsidering this was posted over two year ago I'd say the project is done by now.

yes you can get SE wire from the electrical supply to run overheadSE is not run overhead.

In one post you are asking about running 100A from a 100A service, in the next you are giving electrical advice.
Where are you getting your facts from?