You don't mention all your fish - I looked at the video posted on your journal
You could do a standard fin angel (you've some fish that would nip trailing angel fins so avoid any veiltail & certainly any "long fin" (hopefully no one is breeding "long fin" anymore)) - they should spend more time in the open water (unless intimidated by the rainbows ... not a combination I'd recommend) than rams generally do.
If you begin with 6-8 juvenile & raise them up in a tank with smaller tankmates, adults are less likely to view those fish as snacks - from the group, select fish to keep that are more laid back (if possible go to a breeder & let them know what you're looking for, some lines can be much more aggressive/mild than others); some angels cohabit with shrimp, some are avid shrimp hunters (note this can apply to rams as well)
I've had angels that ignored tankmates they'd grown up with but hunted & (quickly) annihilated new additions to the school (same species, similar size)
I'd likely try
M ramirezi - pick up 6-8 juveniles, you may end up with a stable group (most often my experience) or need to separate out a pair (except these fish don't "pair bond" longterm so it's often a hit & miss) - try to find locally bred or buy from a shop that is careful with fish selection
In general the wild type "blue" ram or "Holland red" seem to be the "sturdiest" farm bred fish, golds can vary, avoid any balloon or long fin variants, electric blue/neon blue can be nice fish but they are often less resilient & "shyer" (I'd not mix them with rainbows or "tough" rummy's (different species are sold as rummy's & they are not all equal)
Rams will be in & out of the thickets more so than open water, though they'll also patrol the tank - depends on the individual character & bloodline (I've had electric blues that rarely venture out when lights are on)
These fish are among the species with iridovirus (terminal once "activated") so again I'd only buy from a specialist fish shop.
If you like to add new fish regularly, be sure to use a quarantine tank (4-6weeks!) or avoid angels & rams.