I'm new to this technology. Old TV pic tube went green, so getting an LCD. Not much on pay TV (HBO, etc) but like PBS and family TV/movies. What older model Roku would accommodate our needs? Is there parental control with any of them?
There are no parental controls on Roku other than a passcode that prevents ordering of channels and games.
But, if you only have channels you approve of, it should work out for you. Lots of PBS, PBSkids, and other "family" channels. I would suggest the Roku 1, 2, or LT because they can be used with any TV.
Exactly this. Roku 3 will only work on TV sets with an HDMI. I'd like to add that while the Roku 3 is a nice machine, it includes a lot of things that really aren't important. The games aren't any better than what you can play on a used 16 bit game machine, the Cat 5 connection doesn't provide much better connectivity than wireless (if you have wireless n) and the USB port doesn't add anything if your TV / DVD / Blu-ray player has a functional USB port.