I have a ppc mac mini which I am planning to turn in to a media centre.
I am interested by MythTV and was wondering if there are any diffrences
between installing mythTv on a PPC linux distro and an x86 based one. I
would imagine they are equivalent but just wanted to check.

If it is just the same then are there any diffrences in the devices I
can use for video capture? I suppose what I am asking is if there are
linux drivers avaliable for a usb capture device can I use the same
ones that I would use for an x86 linux?