I've also been looking into this for my recently purchased VI.
I wasn't able to find people that are able to send tunes by email directly to you and your car, so what you've said are the first I've seen. I'm thinking the biggest difficulty with it is they would need the current log of your car in a test run before they can send you a custom remap, which to do, you would need the EvoScan software and the tactrix cable for your OBDII port. However I could be wrong.
Also a general consensus I've found is there isn't a lot of support for professional tuning of the pre-E7 ECU's, most people in other forums saying they just upgraded to an E7 ECU in their E5's or E6's. However I was able to find a thread
here which gives you access to a downloadable remap of your ECU (obviously still requires EvoScan) and is designed for the E5/E6 ECU. There is a lot of technical jargon (modifying connector pins with switches etc.) that I have yet to sort through however, and would need to do a lot more research before I felt comfortable installing it myself.
Down the road, when I'm actually considering a remap, I think I'll just be getting EvoScan, the tactrix cable, and ECUFlash and then researching the hell out of it in order to amateur-tune it myself. I read this entire
thread and it's starting to make more sense now that I'm on the second time through. Basically you start small and your tune eventually builds up, rather than a professional one-time-go at it. Obviously this would mean a lot of logging, but I think it would feel pretty rewarding in the end.
Basically, I'm pretty sure you're going to at a minimum need EvoScan and the tactrix(2.0 I believe) cable no matter which path you choose.