Any of those you tiny computers you mentioned are good choices, but I would add that you definitely want to stay Intel 7500t or greater as those generations’ quicksync chips are significantly improved for transcoding. Secondly, while I run an HP elitedesk, if I was starting over I would go with Lenovo as some of the higher end boxes like the m920q have a pci-e slot that can be adapted to use a GPU if in the future you decide you need it.
Any of those you tiny computers you mentioned are good choices, but I would add that you definitely want to stay Intel 7500t or greater as those generations’ quicksync chips are significantly improved for transcoding. Secondly, while I run an HP elitedesk, if I was starting over I would go with Lenovo as some of the higher end boxes like the m920q have a pci-e slot that can be adapted to use a GPU if in the future you decide you need it.