Indoor lighting

We recently moved to a Geezer Farm in Colorado from Santa Fe, NM.  I left my greenhouse behind and gave away my echinocereus and echinopsis.  And now it is time to start growing cacti indoors.  Space is a limiting factor.  Any suggestions on lights and lighting?  Are side reflectors necessary or does light from above suffice?  LEDs vs plant spectrum fluorescents?
Any and all help appreciated.
Thank you

I don't have any direct experience of growing cacti indoors, though I started a thread on the BCSS Forum in 2016, though this was initially aimed at propagation of seeds. It does seem to have resurfaced and now seems to be a rather technical discussion about things what I know not of!!
A friend of mine used to over-winter his plants in a spare bedroom, but as that was when the plants were dormant, light levels weren't too much of an issue. When they started to grow he put them outdoors, without any greenhouse. It did mean a shorter growing season for him, and occasional losses when there were unseasonable frosts in late Spring, but this was in Belgium, so probably not the sort of temperature swings that you might have in Denver.
Will your plants just be in a spare room? As I have no real experience, I'd probably start with led lights at about double or treble the usual domestic lighting level, and see how they go.
Hopefully others here will have more knowledge than me.
Btw what is a Geezer Farm? I guess a retirement home of some kind?