I tried shrimp once, and the smell can get pretty ripe in just a few days
Pure ammonia is probably the quickest and easiest way to kick start things. Not sure on where you live, but Ace Hardware sell a pure ammonia that I use and a number of people here recommend. Seems to be the about the safest option for bottled ammonia.
Is that actual live rock or base rock? With live rock you should see your tank coming along pretty quick, but base rock will take a long time without something else to help seed it. I ended up with about 35lbs of base rock in my 20g long and then added a 5lbs piece of live rock later on as the base rock was just taking an age by itself.
And what kind of HOB