Development of Boilers and heat exchenger -- 2

Hello i have to repost this project due to the fact that it has expired as i was away abroad. I need someone with knowledge of UK code and requirements for boiler manufacturing and heat exchangers, someone who can make efficiency calculations and has ability to produce technical drawings and 3d models There will be 3 ranges of solid fuel burners (Wood stoves), they will be separated by output 6KW, 10KW and 15 KW. Each range will have 3 models a. Radiant Model b. Radiant with boiler c. Radiant with boiler and cooker The idea is to create design where all parts of more complex models can be fitted into the same basic model of the range to make it cost effective and simple in production. I see it as initial stove build from Mild steel, hot air to water heat exchanger that fits into basic radiant model and converts it to next model ,, Radiant with boiler,, will be made of copper. Finally mile steel stove will be cladded with Stainless steel which will help with circulation of air around stove as air will be in between two vertical walls and naturally will rise sucking colder air in from the bottom.