I read the original requirement as 8A so one of those should be fine (~1W dissipation). My quick search shows it to be a little bit cheaper than the IRLB8743 so back to the OP: where are you located and what are your cost constraints? Would something like the STP60N3LH5 be easier/cheaper for you to source?
Back to your sensor question (since this is the Sensors forum
), you mentioned wanting at least +/- 0.5 deg C accuracy but the TMP36 appears to only be +/- 2 deg C. Is that going to fit your needs? The DS18B20 robtillaart mentioned earlier does spec +/- 0.5 deg C accuracy.