For the amounts you would need to generate amonia, you would save a fortune buying it at a garden store. Just get amonium sulfate, you can get 5 pounds for about 5 dollars, with no questions asked. At a chem supply there is always a possibility of having to answer questions(no fun!). Even though amonia chloride and amonia sulfate are insanely common chems, dont put yourself through the hassle. This is just something thats just easier if its done OTC.