Purchasing a Mac Pro...

Nope, you can move everything over using the built-in utility of "Target Mode". There are several other options although this method is supported by Apple. You may also consider buying Apple's One-to-One service and they will do everything for you, or you can have them walk you through the process and much more.

In fact, I've been using the Mac system(s) for 25-years and I opted for their service so as to better utilize more of the features that I simply didn't bother with until now. For me, it was well worth the hundred bucks.

http://support.apple.com/kb/HT3322

Note that some applications "lock" themselves to specific systems and have to undergo a special transfer procedure to be moved to another system. Such apps are pretty few, though, and the documentation for the app should specify the transfer procedure. The only non-pro app I know of which such a procedure is the eBay-related app iSale.

For most other applications, you just have to remove the app from your current system (this may be a technological limitation - some applications check serial numbers on the network) - or just legal (i.e. licensing to only one computer at a time).

Regards.