pneumatic foot valve

Hello, I'm looking for a reasonably priced, foot operated variable flow valve for a planishing hammer I'm attempting to build. I believe it needs a 80 to 120 psi range. Its just going to be a low budget hammer for fabbing an ocasional motorcycle gas tank. Also, any reccomendations on the proper air hammer would be helpful. I was just planning on using a mid range ($50-$80) northern equipment hand unit but my mind is open.