Controlling bed-side lights with push buttons

This is a project for a friend.

From his email:
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1. It will have a mains input/socket
2. It will have two mains outputs/sockets - OP1 and OP2 - maximum envisaged 1A
3. It will have four buttons/switches (non-latching, spring loaded or touch-sensitive) which will works as follows:

Button 1 - Will switch OFF OP1 IF IT IS ON, Will switch OFF OP2 IF IT IS ON
Button 2 - Will switch ON OP1 IF IT IS NOT ALREADY ON, Will switch OFF OP2 IF IT IS ON
Button 3 - Will switch OFF OP1 IF IT IS ON, Will switch ON OP2 IF IT IS NOT ALREADY ON
Button 4 - Will switch ON OP1 IF IT IS NOT ALREADY ON, Will switch ON OP2 IF IT IS NOT ALREADY ON
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This is basically a 4 to 2 binary encoder as far as I can see. It's the sort of thing those mechanical channel switches on old TV sets used to do.

I'm thinking of using a 4 to 2 encoder driving a couple of TRIACS or similar.

Any alternatives or criticisms?

Gareth