So if you're serious about this just being as cheap as possible, then an idea occurs to me which it is perhaps silly of me not to have considered earlier. Make two rings that respond to the same command word, and use different specs for each.
Ring of Energy Body: (1 x 20 x 1,800)/(5/10) = 72,000 gp. (10 charges/day at 20 rounds each)
Ring of Angelic Aspect, Greater: (8 x 20 x 1,800) / (5/1) = 57,600 (1 charge/day at 20 minutes each)
So you get two rings, each keyed to activate on the same trigger word. Perhaps "Velaritas'. Each will last for 20 minutes/day. Make a modified version of the Energy Body ring that expends all of the charges at once, or else has a duration pool that can be spent a minute at a time, and you've got twenty minutes of both spell effects at the cost of two rings slots. Mind you, I'm still assuming Energy Body has damage and healing as if cast at level 1.
You can even require both rings to be used by a good character and reduce the cost by 30%.
Total project cost: 129,600 gp. If you can get the Good Aligned reduction, then: x .7 = 90,720 gp.