I needed an inexpensive USB DAC over the holidays for a system I was gifting to a relative and went with Dragonfly DAC. The price was right and I've used one for several years in my desktop system and its worked well for me. Since you mention a kids room, be sure the form factor works.... the dragonfly plugs into PCs USB port and sticks out a few inches, making it vulnerable to impact. Also note, there is a 1.0 version that is discontinued, but still available for reduced price.
I've had an HRT streamer in one of my systems for a number of years and it has worked flawlessly.
No experience with Modi-2, but it would be high on my list.