I can help you out with getting a MB Star Diagnostic system. I have a lot of experience with setting up these systems. The C4 (MB SD Connect C4) units are nice because of the LAN cable connecting the unit to the laptop, as with high quality electronics there seem to be no problems with these units. I do prefer the MB Star C3 units just because they seem to hold up much better than the MB SD C4's. The only downside to the C3 multiplexer is the requirement of a serial port on the laptop and the big bulky cable that goes from the head to the laptop. Software: Many of the chinese setups you see that sell you a hard drive and "will work with any laptop" are just VM ware installations. Basically a virtual windows setup.. There is no reason to go this route, they are prone to crashing and much slower than native (software installed strait into windows) setups.
There are many different versions of the MB Star diagnostic software and each have their up's and downs. You can get the 2014 software that will work with cars just being pulled off the ships. But most people wont be working on the latest cars so I always suggest older versions from 2010 to 2012. As the software keeps being updated by Mercedes they remove more and more features limiting what you can do as far as basic programming goes as well as other small things here and there.. You can be able to SCN code control units with one of these setups. Mercedes has everything setup to connect to their internet databases for verification to do SCN coding and requires a license you need to purchase.. It is technically possible to do, but for most independent shops its not worth the cost. Basic coding/programming of control units can be done with these systems, but like I said you cant do everything.. Of course these systems do all your basic reading erasing of codes, they have guided troubleshooting in them as well. You can actuate components and read data outputs. Im sure you get the picture by now.. These can be setup on pretty much any laptop you want with some limitations. SSD drives or just normal hard drives.. makes no difference when you are doing everything from scratch like I do.. If your interested in purchasing a system feel free to contact obd365.com. They will answer any questions you might have and can figure out exactly what kind of setup you want. They also provide a 1 year warranty on all my systems, which is something you don't really get when your faced with shipping a package back to china and hoping that all works out.