I'm considering using wet underfloor heating in our newly installed
conservatory. It will be an extension of the existing gas central
heating system (radiators in rest of house) driven by an on-demand gas
boiler (no water tank).

The conservatory is 4m x 3m, glass/dwarf walls on 2 sides, was
designed to be a warm living room (e-glass, high spec, insulated etc.)
and to building regs. It will have a suspended wooden floor (joists
and boards NOT concrete slab) because the garden level is much lower
than the house and we want the floor at house level. However this not
constructed yet so heating can be included into the design.

How viable is underfloor heating in this situation? Or should I just
install a radiator (using precious wall space)? Any recommendations
for products and suppliers (considering DIY since did all the building
work)? Useful web sites? Will underfloor heating work?

Advise, experiences, possible problems and suggestions welcome.
Dave