DAC's, i'm lost


I recently purchased a pair of PSB Synchony two speakers along with an NAD 375BEE amp from my local dealer. My audio source is currently my laptop/an airport express. I'm looking for suggestions with DAC's. My budget is 500 and can be persuaded to spend no more than 1000. Please, help a newbie figure out what would work best!!!
mcgarrjr
Great recommendations above. Haven't owned or heard a Tranquility (sadly), but I thought it was worth pointing out that it is limited to 16/44.1 (CD quality) output. Most other DACs here can do 24/96 or 24/192. The significance of this will depend on whether or no you will be playing hi-rez files. That said, the Tranquility also has a wonderful reputation, and I believe there is a trial period for these DACs. And ultimately, this will be about which DAC sounds best in your system, according to your audio/musical preferences.
Logitech Squeezebox Touch for $300 or less. Nice DACs and amazing performance for the money. I love mine, and when I plugged it into a friend's system (he has the same speakers as I do) bypassing his new Wyred4Sound DAC, we were both amazed at the high quality of the "Touch"...it has it's own sound and somehow it works.
The new Rega DAC is $995 and sounds great. It may add some bass to your speakers and open up the highs a bit more.

I'd give Lavry Eng a call. I'd also bet it a very good fit for your rig.

Regardless, I'd also keep an open mind... and find one which will integrate well with a PC. Do those higher bit rates, and has great flexibility along with a sound which works with your gear.