Which Potassium Product?

[<7%]

Which of these three potassium product is best to take:

1- Potassium Citrate
2- Potassium Citrate Tricitrate
3- Potassium Carbonate

I found number two on E-Bay and it appears OK for human consumption; don't want to give a direct link as it may be against the rules, but it is there and very easy to find for those who are interested in reading more about it. Sold in bulk and price is good too...
Also, what is the maximum safe amount for potassium from a supplement?

Thank

[<7%]

bumpy

[LouB2010]

eat a banana

[Oscarizo]

Potasium is in almost every food, why use supplements for it.

[AchieveABG]

Potassium (i think its potassium chloride) can be found in salt substitutes i.e. NuSalt or NoSalt. They have around 500-600mg per serving and cost $1.99 per shaker. Available at any grocery store.