I would agree look for the lowest miles and best unmodified one you can afford. These cars are either use and cared for well or trashed. With mods it is a crap shoot unless you know the car. Many do a good job but others can do a lot of damage and then bail on the car leaving you holding the bag.

 

I have a stock auto, use it for work at a house for a couple of developmentally disabled guys who get plenty of seat time in my little red wagon. For the commute to and from work, plus the on-the-job drive time, I'm very grateful for my slushbox after many years rowing manuals (at 50-years-old, my creaky left knee ain't what it used to be).

I've considered the GM Upgrade many times, but the reality is the car feels plenty fast as it is. Maybe if I was autocrossing it would seem more important to me. You're better off finding an unmodded SS, then deciding for yourself if you need the tune. For your driving situation it may not be necessary.

 

I meant to say automatics RULE. LOL

 

The SS was bought to be a fun DD that got good mileage, not a track star. FOR ME, a manual is more fun. My panel just happened to have the RPD, so no choice there, but being able to monitor more parameters is always better (again...FOR ME). I had the performance seats, but didn't like them, so a set of Corbeau's went in.

Test drive all you can, and get what you like.