Jungheinrich had a truck with rotating cab on the market a few years back ,strange looking machine. Hyster/yale have a seat that swivels about 30/40 degrees on small range trucks.

Linde brought out a rotating cab a few years back but I know for a fact Jungheinrich also have a model on the market now

Thanks, I saw a Hyster truck. (I think around 9T range) with 180° rotating.
Seems they are only available on bigger trucks that have more space to get it in.
We are seeing more and more complaints of stress/strain with operators driving in reverse with the prevalance of H/S in the workplace.The introduction of swivel seats hasn't solved the problem but only made operators more aware.

Kalmar has a rotating seat as a standard option, the Kalmar range of machines starts with a capacity of 5000 kg, nothing smaller, we have delivered a number of machines here in Australia with 180 degree seating and feedback from operators is very positive

Yale has neat system

You could use a rearview camera, have a look at

http://www.orlaco.nl/film-achteraanzicht-stackers.htm
and
http://www.abbey-attachments.co.uk/camsys.php

Linde did have a pivoting seat on a unit as I recall when I saw it in 2002/03 in the US South Carolina facility. The operator's pod was elevated above normal sit down position & it seems to me the controls (foot/hand moved with the operator.

Jungheinrich did have a truck at the IMHX a few years ago where the cab rotated but i don't think it made it to production.
Apart from that I have not seen anything else and you would not be able to retro fit anything that went 180 degrees because of your control pedals.