Gellert Magnus is pretty cool and hip sounding!
Gellert Ambrose is more distinguished, I think. I like it a lot.
Gellert Amadeus is gutsy and awesome.
Gellert Valdemar is too hodge-podge for me. The two just don't fit together well.
How about
Gellert AveryGellert EmeryGellert EvanderGellert Callahan (ooo to the double double Ls)
Gellert Flynn or
Gellert FinnGellert JosiasGellert MacKinley
Gellert WhitakerGellert SullivanGellert Montgomery
Emrys Frederick is very handsome and well-balanced.
Emrys Arthur is also nice but flows less well.
Emrys Theodore is an interesting pair. I love both names, but I don't know about whether they belong together or not.
How about
Emrys Gellert (not the point, but I do think it works)
Emrys TennysonEmrys OdellEmrys JoachimEmrys GallagherEmrys Declan
Three boys nappin', one mama namenerdin'
To peruse my top 100ish names:
http://www.behindthename.com/pnl/82589
He is becoming greater, I am becoming less
Bits of the journey here:
http://jodifriesen.blogspot.ca/And some family cuteness here:
https://www.flickr.com/photos/41705228@N08/