Is there an action replay code for all stamps on legend of Zelda spirit tracks?

No, there isn't. You shouldn't cheat, but I will tell you some of the locations I can remember:

Stamp locations:

Outset island (sorry for names I cant remember them)

Castle town

All the temples (forest, snow, ocean, fire and sand)

Sorry those are all I can remember. If you get 10 stamps niko will give you an ancient shield, which cant be eaten by like-likes or rupee-likes. 15 stamps will get you your enginiers outfit, so you can change between your starting outfit and the recruit uniform. All 20 stamps will get you the sWordsmans scroll II, the great spin attack, draw circles around you three times to unleash it, but it immobilizes you for a few seconds afterward, so your open for attack.