4 heatpipes of the recommended Nine Wind God Ice Ling 400, Cooler Supreme Storm S400 about 100 yuan
3 heatpipes of the recommended Simin CNPS5X Neptune Halberd about 70-80 yuan
The same number of heatpipes depends on the number of fins and the area of the heat dissipation, you can go to check it out.
Going online will be cheaper. Overclockers are not very cost effective and not recommended.
It's important to note that the silicone grease is applied, not a lot, but very evenly, and the fasteners are not too tight.
Good luck.