In addition to keeping the above in mind, you should also consider that poly is a stiff string and it will bite the ball if you have good mechanics. A jump to that thin a gauge might be overkill and hard to adjust if you haven't used it before... i say go for a 17g or so poly, they've got plenty of bite and plenty of durability...
There are a few good ones out there... If you want to go for cheap you can try the Tecnifibre polyspin, it's a solid performer, although i preferred Wilson's polylast to it by a long shot (they no longer have it)... Babolat's polymono was probably another close competitor, just about any cheap poly loses tension pretty quick, but i don't mind it and they all play fairly similar.