There are a few used ones for sale on the forums.
MakerX DV6 - $175
Focbox Unity - $170
Spintend UBox 75v V1 - $175?
Spintend Ubox 100v V2 - $265
Any will work, but the first two are probably better choices if you want small size
DV6 is 106 x 71 x 23mm
Unity is 117 x 68 x 19mm
Good suggestions above on remotes. Some more options for remotes:
Z.Mote - been 100% reliable for me.
Tried a VX4 recently. Was actually pretty nice. Early ones had some firmware issues?