By the way, I've always said that getting 18-24 VDC @ >30W for either the FE-5680A breakout board or the GPS Discipline module ought to be as easy as getting a surplus laptop power supply. The white ones from a certain fruit-themed computer company are an excellent choice, and you can send the magnet attachment parts to MikeGuyver.
But if you really want to buy a new power supply (or if that's your only choice), DigiKey does stock a few suitable ones. A particularly attractively priced one is the CUI ETSA240170UD-P5P-SZ. Unfortunately, it's EOLed, so there's no telling how long they'll be available. A direct replacement is the SDI50-24-UD-P5, but it's a little pricier.