Since it's mostly music, I'll spend your money for you. Pick up a set of these before they are gone.
Canton 836.2
www.accessories4less.com
Canton LS860 stands (unless you already have a place to sit speakers)
www.accessories4less.com
That will eat up your $1,500 budget but you'll have an awesome sound stage with a set of bookshelf speakers that are capable of digging deep and that have very accurate, smooth midrange.
If you can squeeze a few more bucks out of the budget now, or in the coming months, add a new sub equivalent to your room size and a newer receiver (if needed) for more power. Maybe a nice integrated 2 channel if you are not watching movies.
EDIT: Based on your large room size, you may be better off going with larger floor speakers but regardless these bookshelves will be awesome for music. For that sized room, the above speakers with a couple of PSA TV1512 subs and an AVR or integrated Amp with decent 2 channel power would make an excellent music setup.