New boat... need to get maintenance up to date.

Good afternoon,

I purchased a 2000 21v Tige Monday. Mercruiser 350 black scorpion 330hp with 400 hours. I ran the boat initially with no issues. Second time out trans fluid light comes on... check trans, milky oil. Flushed it out. All other fluids are good.

Third time out no issues with trans. Boat overheats, i never let it get above 190. I shut it down, checked water intake, all good, let it cool, went for another spin. Hot again, killed it. I went to ease in and the boat started, sputtered, died. Wouldn't fire after that. Took it home and let it cool. I removed the fuel cap to see if the gas tank vent was blocked, didn't notice any air being sucked down but it was noisy around me. Backed it into my local lake, fired up and ran fine.

Before i run it again i want to do all of the maintenance top to bottom, and most importantly, the cooling system.

1. oil change
2. thermostat
3. water pump
4. impellar
5. vent hose

I need help with two things... part numbers, and what other maintenance do you suggest?

Thank you,
Sam