i run a small general repair shop in mass, i have never woked on a a6, it is a quattro, with 115k, the timming belt seems to have jumped after the car was started after it sat unused for a week or so, i t appears to have valve problems, i get no compression at #1 with the valves closed, so my question is what kinda job am i getting into, i have done many, many top end jobs, also should i maybe consider replacing the eng?

 

You need to pull both cylinder heads and have another shop do the valve work, un-less you have the special tools to overhaul the head, its a pain in the ***.
You shouldn't need a new engine, usually the pistons get a small knick but they should be fine.