Hi Andrew

[...]
eventually. So given that the current Centre lamp is a 65W 5 foot
strip, what sort of uplighting wattage should I be thinking of?

You should paint the ceiling matt white (titainuim dioxide) for
maximum reflection and diffusion. Also make sure tops of cupboards
are white (doesn't need to be matt). You will need more power
because of losses at non-perfect reflective surfaces.
What is the length of the cupboard run?

about 2m. Do you use reflectors on the indirect lights, or just allow
the light to bounce around?

Are you thinking of any other lighting in the room, such as
under cupboard, down lighters or uplighters on the other side
of the room, etc?

I'm now, after this thread, thinking of keeping the current
centre-of-room cable, and fit some sort of directional multi-bulb
fitting, as well as the top-of-cupboard lighting.

What height of object is the largest you can stand on the top
of the cupboard at the back, and yet it not be visible when you
are standing at the other side of the room?

about four inches - I can just see the top of the extractor hood pipe.
There is about another six inches of clearance above that.

Would you drill through the joists to carry the cable across or is
there a neater/easier way in this instance?

Thanks for your thoughts.

Jon N