I would have to agree with Neunerball - a mech is a bad place to start.
If you think high power is where you want to end up once you understand the risks and how to mitigate them, I'd suggest starting with a regulated box mod - there are plenty out there in the 50+ watt range available cheaply, and they can be vaped with a tank and upgraded to a rebuildable device as time goes on. The bonus is that you'll have something safe to test your early builds on before popping them on a mech.
Read up some on battery safety and get some good batteries and a charger - get the ones with the highest (reliable) continuous amp rating you can find if you're going to move them into a mech at some point.
Welcome to VU, and good luck with your search!