Rick Hughes :
Not very D-I-Y ... but there are some knowledgeable people here.

I recently bought a Samsung Smart TV - 46ES6800 ......... having
struggled using remote to drive for example Web interface, realise I
need to get a wireless keyboard with built in mouse.

Will any wireless keyboard work ... assume that you use a dongle which
plugs into back of TV, into one of the USB ports.

I'd be surprised if it worked. Some USB sockets are provided simply for
reading storage media and not for other purposes associated with
computers. I'd expect those on a TV to come into that category.

--
Mike Barnes