I have been after a ute for a while, but am now considering getting a wagon and doing a slight modification, ie. chopping the back off, and attaching a ute back (probably shortened), a sort of dual cab. How easily would this be done?
Your definition of "slight" and mine are very different! I've never seen this done to an FE or FC, but there are WB and HQ-HZ Kingswoods that have been customised in this way. It all sounds straightforward enough, but bear in mind that the sides of a ute are much higher than the window-frame level in a sedan or station sedan, so do you build them up so you can use a ute tail-gate, or leave them low and looking 'not quite right'? And how are you going to finish off the rear of the cab? I reckon you are going to need a good condition wagon, a donor sedan and a donor ute to have all the bits to cobble together.
Check out Unique Cars magazine for the HQ-WB dual-cabs: that should give you an idea of cost of this style of project. I've seen three or four utes for sale in the last month - I'd keep looking for one of them if I were you :-)
cheers RET