100 gallon needs changes!!

There are not that many large fish species that will not eat tetras (of course large is a relative word). The only large fish compatible with Tetras that I can think of at the moment are Discus and Kissing Gouramies

If you are welling to compromise a little on size, then other Gouramies would also be a good choice since most reach a respectable size though I would not call them large

Just note that you should always add the smallest fish you intend to keep first and allow them to get established

i would just add the tetras...

some of the tetras cam be large comparitively, if you can find columbian blue tetras they get about 2 1/2 inches and are quite nice... bleeding hearts get to a good size as well... diamond tetras get over 2 inches
heh the ember tetra maxes out at less than an inch and there are many that are in between these in size
so when you say you want a center piece that will not eat these it depends on what size tetras you want

really some tetras are almost large enough to be center pieces as a small school

IMO a tetra that is just big enough to be safe with the angels would look nicer, make the tank look bigger, and you would be able to have more of them. then I would have a small school of a large tetra for contrast.

another thing to consider is habitat level in your tank. black phantom or serpae tetras(I don't recomend with angels, serpae's can be mean little buggers) both are lower level swimmers, while a lot of the other tetras are mid tank

trust me I have dreamed of my own tank of that size and restocked that dream countless times lol

one final question and a suggestion

how big are your clown loaches and would they make the tanks fish waste production go to high if they continue to grow like they are known to do... you can expect them to reach at least 8-10 inches in the long run.

I would start by adding the larger tetra first to get the tank mates used to introductions wait a bit and gradually bring the numbers of the smaller tetra's school up till you think it is good keeping in mind that if you get young fish they have an adult size that fills more room

start each school out in the tank with about 8 fish and then add more

as for the total # of each hmm you said you wanted a school swimming in and out of your plants... to many and they will be every where at once, to few and you won't see them as much as you like
8-10 of the bleeding hearts, and 16-20 of the rummies, I have suggested a lower # of them and here is why, you have removed fewer but larger fish, and these schools are going to fill a larger space in the tank, you haven't said whether your angels are pairs or not but if they decide to pair up that is going to take a sizable chunk out of the space in the tank, and last if after these smaller schools are full grown adults or aging you can add some more young fish to those school to add variety and not be pushing it

but I would let a smaller # settle in for a while before adding as many as 46 more fish we can't say what the social limits of the fish that are already in the tank are so I would build up to it while keeping an eye on the behavior of the inhabitants of the tank

if they start changeing what they do on a regular basis cause ot the new introductions then you have introduced a stressor and as far as I know to the best of our knowlege we try not to do that