i was wondering if it was possible to use the stock seat brackets from my 99 Si, for the brackets on some Tenzo Rally's???? or will i need to buy the other brackets??

 

you'll need brackets. the stock seat brackets already have the sliders on them while sliders are built into most aftermarket seats. you can buy brackets for about $80/set on ebay.

 

do you have sliders already on the seats?if not,you can adapt the factory rails/sliders to your new seats.i've done this on a few Sparco/Momo seats.
do a search on here and you'll find a few threads about fabricating seat mounts with simple pieces of steel you can get at Lowe's/Home Depot.
Chris