I use a D-18GE. I love that guitar. Although I think the Collings D1A is a better guitar, it is also about twice as much as I paid for my D-18GE. I also played a Santa Cruz Vintage Artist(pretty sure that was the model name) that was a killer guitar.
Buffalo Bros is a good reliable shop. I personally have bought 3 guitars from them and alot of my friends buy there too. Also check out the upgrade policy, its awesome.
Ive had both a 410-ce and a 514-ce and both have been great guitars. The 514-ce is by far the nicer guitar. I got mine for 1500 so im sure you could find some within your price range. Although bluegrass and blues are not its specialty IMO, thats more Martin territory. But all in all definetly...