Unfortunately $10k is a drop in the bucket. I pay tangible taxes on nearly $400k worth of equiptment. I have over $50k in scanners alone.
But given your question I would start with a good DSO. The Fluke 98 (see my driveability article in DIY) can be had used for around a grand (they are on ebay all the time). It doesn't do ignition as well as a dedicated tool but I paid $20k for my engine analyszer - Bosch Mot250 and you will need some money out of that 10k for a scanner. A scanner alone will not fix cars, it will only guide you if forming the proper testing for your DSO.
If you really want to do it right I would suggest the Vetronix MTS5100 for your scope. It will take a good chunk of that 10k at around 7k and its too new to find used most likely. That doesn't quite leave enough for a Baum CS2000 although they may be found used and a new module added. The current MB module lists for $1.5k (the base tool goes for about $2.3k). If you would like to view these tools see: