I have to admit i like the kind of frosting you described. It's what frosting was when i was a kid. Real meringue-based buttercream was a discovery i made in high school when i started to go to Boston and to the "patisserie francaise" on newbury street and then was overwhelmed by the cream puffs that were actually filled with buttercream. Yeah, can you imagine?
Anyway, it's not hard and not complicated. I never had a sugar thermometer, always used the method where you drop some in a cup of cold water and see how thick it is.
The main things to be careful of are to make sure you don;t have any grains of sugar in the syrup - so you boil the water and sugar until it dissolves swirling the pot by the handle - don;t use a spoon because some grain of sugar could remain stuck to it and then ruin the syrup (one crystal of sugar will make the saturated solution solidify in crystals instead of staying soft.)
Then once the sugar is completely dissolved you lower the heat and cover the pot tightly (so that the condensed water that accumulates on the lid slides down and washes the sides of the pan). (alternately you can wash the sides of the pot with a wet brush)
Then you should beat the egg whites (they say to put a pinch of cream of tartar but i rarely bother) until they form soft peaks,
Then you uncover the pot and raise the heat again, and boil for a few minutes until you notice the bubbles getting slightly thicker - get a large cup with ice water in it and take a clean spoon and lift a bit of the syrup and drop it in the water. At the beginning, it will just dissolve into the water. Then it will splat on the bottom but you won't be able to pick it up, then it ill form a thick splat on the bottom and when it's thick enough to pick up and form a soft ball in your hand, you remove from the heat, start beating the egg whites again and very very slowly pour the hot sugar syrup into the meringue while beating, in a thin stream, until it;s all used up. Continue beating till it;s room temperature, then beat in about two cups or a pound of butter into it a little at a time. .
Here are the proportions
1 cup sugar
1/3 cup water
pinch cream of tartar (i don;t find it really necessary)
up to 1 pound or 2 cups butter softened to room temperature
vanilla or whatever you like for flavoring.
3-5 egg whites
I usually use less butter. The meringue itself, without any addition, is a great light frosting, or you can add a cup of heavy cream, whipped to peaks, into it, and you have a very stable whipped cream that has something particularly soft and pleasing to it. If you put this in the freezer you have an ice cream that will never make crystals and will remain soft without using an ice cream freezer. You can beat melted chocolate into it after you added the sugar and then beat till room temp and then add the butter, and you have chocolate frosting, or you can add whipped cream to the chocolate and meringue and make chocolate whipped cream that's very stable and soft, or you can change your mind, put it all in the freezer and make soft chocolate ice cream.
Anyway, you asked for buttercream, so add the butter, and see how you like it. You can add less, the meringue is very stable and nice on its own, so no need to use the whole amount if you don;t want it too buttery. Just add a little at a time and stop when it tastes like you want it to.
This has a silky feel to it on the tongue, no powdered sugar feeling
try it, it's really not that hard. The directions are long so you can't make any mistakes.