I've used this one for the office, and a similar (smaller) one for the hallway.
Led Wholesalers Waterproof Electronic LED Driver Transformer 48 Watt 120 Volt to 12v 4 Amp
If you just do a google shopping search for 48W LED transformer (or whatever the wattage you anticipate needing is
, these pop up. They're fully electronic, so they have a high efficiency and low heat output, have built-in overcurrent and short circuit protection, and work well