Transmission upgrade?

[wilfred]

I am debating if it's a good idea to use my '03 for towing? Thinking about picking up an used Miata for track which is roughly 2500lbs + an open trailer in which I've been told is roughly 1000lbs. I know I shouldn't worry too much since this is only half the maximum towing capacity but given the fact few ppl here had experienced tranny problems already and the fact our H2s are rather heavy to begin with... I was thinking about upgrading the stock tranny before it goes bad on me?

Now I know they have high performance tranny built for racing. But do they have high performance tranny built for towing? If so, how much money are we talking about?