eyepieces for alter 603...help

Awaiting the arrival of a used Intes Micro Alter 603 (f/10, 1500mm focal length). Wondering what eyepieces to get for it, in the 1.25" range only. Was thinking 32mm UO Konig II, a GTO 7-23mm zoom, and the 6mm UO Ortho I currently own. Any recommendations for EP under $100 used? How is the Intes Micro 21mm 70 deg FOV kelner? Thanks in advance.