I don't want to insult you, so please don't take this post as such (I some times come off sounding like a big ole bag of d0uch3). Even store bought hops will have a varying rang of AA, because of distance travelled, storage conditions etc. My concern with using homegrown hops is that my beer will come out more hoppy/bitter than when I use store bought hops simply because they are fresher and haven't travelled as far, however there is the potential that my hops may not be as potent as store bought because I don't have a farm and my soil conditions are umm far less controlled.
If you are worried about something similar to me (bitterness/hoppyness) then the tea solution is your cheapest bet. Even if you were to send your hops out, the only way for those numbers to be usefull would be if you sent out store bought hops at the same time so you have something to compare them to. However if you are just that much of a beer geek (not an insult, I'm that kind of geek when it comes to motorcycles and cars) and want the figure for you records or to check the progression of AA in your homegrown hops then well the lab option is your best bet. Hope that was somewhat helpful, and I didn't come off sounding like a big ole D-bag. :cheers: