I went Java, but I'd say as a rule of thumb if a broker offers a Java API you'll find C++ and FIX API's as well. Your better brokers will always have API's and I'd go as far as to say if you really are going to do this professionally then you have to use enterprise grade code. Can't do that in MT as you're in someone else's framework.
MT is ok to get you going, but once you've cut your teeth it's time to move onto something a bit faster and more professional.
Also, I don't know why you'd bother with something like Raspberry Pi, you can simply leave your compiled code in the cloud, it will always be on, no bad connections or any of the shit that comes with having a physical box somewhere.