DC Landscape Lighting Transformer
I'm not sure why you're going with DC.  I've put in many systems with 12 volt AC transformers with built in timers and or photo cells. The lights I've used are all LED or incandescent and they run on AC. I've got 15 fixtures in my backyard using LED bulbs hooked up to a 12 volt AC transformer. The bulbs will take AC or DC so I went with the AC. Check with some different manufacturers or do some checking at your home stores or lighting stores. They have plenty of fixtures, bulbs, etc that run on AC.