The E34 M5 Touring was only available in Europe. The ones that are here in the US are federalized cars (read: PITA) or are regular E34s that have been converted to M spec. Those first two pictures is a US federalized car that belongs to Rob Levinson of UUC Motorwerks and is a 3.8L model. Although they came with the "throwing star" wheels seen in picture 2 and 3, the E39 wheel is a common upgrade and is seen in picture 1.
There are two engine types for the E34 M5, an earlier 3.6L with 310hp and the later 3.8L with 340hp. The earlier model ran from 1991-1992 and the later 3.8L model ran from 1993-1994, I think. The US had the E34 M5 for only three years, I think. I don't think we got the 1994 model year and it was replaced by a standard 540i with the M Teknic package, which is all M, but for the motor, which is the biggest part of being an M car.
They are great cars (although I'm biased) and have a great engine note under throttle. Definately a "sleeper" car though, whether it's the sedan or the wagon. I ripped off a flyby on my friend who was doing 130 in his M Roadster. I passed him at 140 with plenty to go. The car is factory limited at 165 and those that have chipped the ECU say it can do up to 170 before drag keeps it from going any further. 1/4 times run in the high to mid 13s stock.
My car:
http://www.bmwmregistry.com/detail.php?id=1177
New, the car was a $60k (US) car. They're varying in price now, dependant upon the condition of the car. There's a lot of poor examples out there for cheap, but you don't want those because the maintenance on the car can be substantial if you're fixing things that the prior owner neglected. It's better to get a higher mile car with a good maintenance history than one with lower miles and missing gaps in maintenace.
You can find them listed in AutoTrader.com if you do a search.