The setup:

56"H - 2.40:1
21' throw distance
I can mount the PJ @ any height as it will be mounted in equipment room behind theater.
Seating @ 11' & 19'
Total light control, but may want some light on when watching sports (or when spouse demands it)

With the RS10, can I go with the ST130? or should I go with the HP?

If we assume the RS10 is 450 lumens after calibration and maybe 100 hours, then your foot lamberts will be just under 12. Maybe a little bit dim.
I just ordered a 54 X 129.50 in 2.40 aspect ratio Dalite Hi-Power for use with my RS20. Shipped today:-)

i have a 1.5 gain with the Rs1 and its plenty bright.

i have a 1.5 gain with the Rs1 and its plenty bright.

What size?