Sorry but i have no idea why the picture is still upside down!!

This is way too deep to install on my zetec (pic below). I need a tensioner for s/c, alternator, water pump and crank (obvs!).

Anything simpler out there? Someone mentioned the cossie type, but that doesn't look like an auto-tensioner.

Assuming blacktop. Does it have to be a sprung tensioner? Easy enough to to make the alternator act as the tensioner and just put an idler above the water pump pulley. I made up a tripod bracket to mount the idler in the right place.

Idlerpulley3

Idlerpulley4

Its Silvertop but i like you're idea. I'd suppose i really need to know if it needs to be auto-tensioner or not as it will have a supercharger on it.

I suspect if you are running a supercharger then a sprung tensioner would be a desirable thing. I think I would still make the alternator adjustable so as to be able to keep the tensioner well tensioned. If the tensioner is going to bear on the back of the belt then maybe a cambelt tensioner could be suitably mounted. Range is small but tension is OK.