I don't really like either name, they both seem kind trendeigh, but they seem to have substance and meaning to you and that is what is important.
Kellyn doesn't read as Irish/Celtic to me, I am assuming it is pronounced like
Kellan which is an English surname with
German origins. I don't think it would be weird on a Chinese-Canadian person, my school (in Vancouver) had a 75% Chinese population and we actually had a large number of immigrant students with Welsh names, like
Rhiannon,
Ffion, and
Gwyneth apparently the English school a lot of their parents went to liked to change things up so that they didn't all end up with the same small group of English names.