This question applies to both freesat+ and freeview+ boxes.....

Are there any boxes out there that have the equivalent to Sky's RF2 output that would enable me to watch recordings on the main box on a subsequent tv?

Topfield 5800 and Humax 9200T are two that spring to mind. Neither is a current model but the 5800 can still be had.

God the Topfield is ugly lol

Apologies, I should have also added.....

'and also have an equivalent magic eye where you can control the box over the RF, or would I be stuck with AV senders?'

There are devices that allow magic eyes to be used with non Sky boxes. See here for example
http://www.satcure.co.uk/accs/page3.htm#tvlink-plus

There are also wireless devices that pass TV signals one way and remote signals the other way.