Thanks for the continuing input guys, It's hard to know what my Dad actually wants other than to "upgrade".
The way I see it is there are three basic instrument catagories.
"church" pipe organs.
"Hammond" style tone wheel organs, designed as smaller, cheaper replacements for pipe organs.
"home" organs, designed as multi-timbral instuments for the solo musician.
Even the oldest pipe organs were intended to emulate other instruments with pipe sets designed to sound like reed, string or brass instruments.
As you can prolly guess, my dad wants the home organ type. He's a wood cabinet guy
If it were for me I would go with Hauptwerk, but you need a complete PC system to run it with screens, keyboard, mouse, midi keys, pedal board, midi controlers, etc.... He wants to just sit down, press an "on" button and
assault everyones ears play away to his heart's content without worrying about booting up a computer first.
I'm going to have to take him on a trip to Peterborough Organ Centre to have a play with their stock.