This chart gives a good overview of current supported phones features.
Small phones, like the old legacy phones, do no really exist anymore.
You would want a Moto or a Google Pixel phone model, if you prefer the Stock android experience.
Note that, if you wish to keep your current Refund based plan, you can not upgrade to any of the 3.0 or BYOP phones, as those require the My Choice Plan.
You would need to find one of the RW specific made Legacy Phone models used on Swappa or Ebay etc.