Yeah, everyone (here) seems to always recommend gear that will be applicable to tech diving, when normally I think the advice makes little sense for the typical person starting out.
However, in your case, sounds like you know what you want to do, so pay A LOT of attention to buying the right gear ONCE.
Tech diving is expensive with respect to time, training costs and specialized gear. I would search far and wide for a suitable local mentor, who might be able to help you make as few mis-steps as possible on your new venture. Good Luck!