What is the bottom line?

should I buy another fan and try to increase to 150MHz and the voltage a bit or just stick with 146?

If you want your cpu to last a long time even with 146 I would get a different heatsink & fan.
Up to you thou.
Btw if you do get a heatsink and fan you will need to get thermal grease if its not incuded.

Have a good night/day

thank you vewy vewy much.