i just need to know what gaskets and o-rings i need to buy before removing my thermostat housing... cheers

Which housing????...top water neck or the bottom housing????
If the bottom one, then you'll need the " Tin " gasket, an 'O' ring for the bypass pipe, and the t'stat seal.
File all mating faces to make sure they are flat and smooth.
Clean all mating faces before using sealant.
DO NOT use sealant on the t'stat seal.

....i used sealant on the thermostat seal....
and the two gaskets for the lower to head & lower to upper i got from repco where paper