I work with theater and therefore have an intrest in lightning .
I have not yet seen any damage done by LED lightning to any matretial . But some of the big LED lamps we use generate some heat. This is one of the resonsons that not all theater lamps are LED. Becouse heat means cooling , wich means fans that means noise.
The thing that you have to thing of when you buy LED is the color . A LOT of the LED shows colors very bad. I have never seen any LED that can give you the color that a normal lightbulp gives you. So be very picky when pick your LED.
I would say don't buy online , but take a cardback with you and go and see it IRL before you buy.
There is some LED that can give you almost the right color. They offen use the term RedGreenBlue. Wich is the main colors There is a nother one called RGBWhite wich they say can mix all collors. But what ever they say it is still not the same as a classic lightbulp. And if you have to mix your own collor scheme . Then you need some control box for it.
Another thing is that some LED's are very bright , so some kind off dimmer system might be and idea. Or you have to be abel to blind off the LED's so you don't get blindet by them . You can do this by making a border in your displays where the LED's are hitten behind.
You mention hallogen lights . I have worked with lightning on museums and in buildings on unesco's world heritage list. They vere VERY ANAL about NOT useing hallogen lights . Becouse it would destroy things.
So i would be carefuld with hallogen aswell
So LED must be the thing to get . But take the color thing serius mate.
Uh another thing . Many camera types have a hard time taking pictures in LED light. Video cams is hard hit hard hit by this . And we have big problems with some live shows . Where the camras are fuck up big time by the LED's
Uh and one last thing. I got this new E27 socket LED lamp as an test from a seller . I used it a day in a lamp on my work desk . The light was bright and good work light . But it smelled very bad of warm plastic . I got an head ache working besides it. And i never have head aches . So if something smells chemical . Don't buy it
I hope this helps you and don't just give you more ? mate.
Feel free to ask if there is any thing you think i can help you with.