Which cAMP and Biotin for chemotaxis ?

Hi,
I would like to do some assays for chemotaxis towards cAMP, Biotin and Lysine. It seems that the preferred compounds are cAMP-NH4, Biotin-NH4 and Lysine-Acetate.
Could anyone tell me where can one get these chemicals ? Sigma and Calbiochem dont have them…(except Lysine -acetate). Also, can any other salts of cAMP like cAMP-tris be used ?
thanks
Rahul