Beryllium center for Avalon Eidolons

I'm thinking of trying a beryllium based tweeter center channel (Focal or Pioneer) for my Eidolons which use ceramic mids and tweeters. Think they will match up okay? Thanks.
generally speaking A focal tweeter isn't easy or at least cheap to get. I know I had to buy some. And speakers are hifgly engineered products that aren't simply one from column a and one from column b attach to crosiossover at point x etc. I think you will run into trouble unles well versed in speaker design and building.
I have the Avalon Indra's and acquired the Kharma Cermamique CeCt-1.0 Center after seeing that an Audiogoner who had the Eidolons and was using the same with great results. It has been a fantastic match for my system. I know they do not come up for sale often, but; if you find one, you will be pleased with it's performance using the Eidolon's. I was previously using a B&W HTM1.
If Avalon offers a matching center for your speaker, that would probably be the best way to go. The center channel is quite important in a surround sound system and needs to be properly voiced to the mains for the best results.

Other than that, the best you can do is to hook it up to your system and see how it integrates...

You might try Salk. He made a center for Edorr for his Eidolons. Salk uses the same ceramic midrange that is in your Eidolons. I don't know how well it worked for him. I do know Jim Salk products have a flat frequency response and he probably can match your Eidolon cabinets at a reasonable price.