We're replastering our lounge and I want to add 3 or 4 thick curved
glass shelves fitted into a corner with no visible supports.

The glass shelves will be a quarter-circle (ie a 90 degree segment)
with an outer radius of approximately 75 cm and the inner corner cut
out at a radius of approximately 15 cm to provide space for the
cables. I'd also like to embed some high-intensity blue LEDs in the
slot so that they illuminate the glass from within.

What I'm thinking of doing is creating a slot in the plaster for each
shelf to slide into by fixing 2 parallel wooden batons to the
underlying brickwork on each side of the corner so that the lower
batons support the weight of the shelf and the upper batons stop the
shelf from tipping forward.

Does this sound feasible?

I want these shelves to support my AV equipment and the heaviest unit
is the amplifier which comes in at about 13 kilos! So I think that I'm
going to need some pretty thick glass! My 'wets finger and holds it in
the air estimate' was to go for at least 25mm glass.

Does anyone know how to calculate the required thickness of glass (or
at least have some experience to provide a better guesstimate)

Any idea of the costs for getting glass cut to size/shape? Any
recommendations for suppliers (I'm near Brighton)

All suggestions gratefully received.

Perry