Western style greenhouse /glasshouse aka sun room /conservatory

Can anyone on the forum recommend a competent builder and also a carpenter.

I will need to have a reinf concrete slab shuttered and poured and on which a wooden frame structure will be built, this to aid in the thermal warming of the villa. The slab will replace a galvanised steel roof on top of the kitchen.

Can decent cured wood for construction be purchased in Addis along with double glazing?

Thanks
ubdai