I have a 5 speed Accord and I want to purchase a H22. Do I have to buy it's 5- speed tranny too?

well you could use your accord tranny, but your best bet would be to go with the lude tranny because the accord tranny's gear ratios are set for cruising and gas saving. the lude gear ratios are meant for performance, so the car will be quicker with the lude tranny than the accord tranny.