Maui

Kia ora Tatou, I work for a charitable organization with a LARGE number of obsolete T5125, xxx35 and xxx45s. As HP no longer support these models, can somebody please recommend a reliable OS alternative - such as linux and able to incorporate Citrix middleware (receiver/ica)? Preferably an OS that is still supported. Has been known to work well on the models listed and if I'm not pushing it provide some basic instuctions how to implement? Regards, @