Welcome to the wonderful world of loose leaf teas! If I had to reccommend some teas from my personal collections:
-TaiPing Hou Kui-there are many vednors you can get it from and I have found that www.springbuds.com
is a good place.....you have to e-mail the guy, but he is real nice and can get you whatever you need
-Any sencha from ocha.com is nice, but if oyu want something cheaper, itoe.com has a "daily sencha" that is $7 for 2.5oz and it is not bad at all
-a company you could look at is teafarm.com......some of their teas are not very good, but I have found some that are....and they are cheap enough to sample and not break the bank
Hope this helps!