Don’t even think of something non WAAS. They are all obsolete. With vor’s going away you want to be able to fly the full suite of rnav approaches as more and more airports are going that way.
The garmin 175 is a great budget alternative to ubiquitous 650s and 750s. Used garmin 430s and 530s are plentiful, but future support is a concern. Take a look at the Avidyne ifd 440 and 540 as well. I have them and prefer they have some features the Garmins don’t. All of this stuff is approved on AML STCs for the 200s