Hello Emma, first of all I do not represent windows suppliers, for this reason I have no intension to sell you specific windows type :) Secondly I am working as project manager and everyday discuss these questions with my customers who are building homes. Mixing two different styles - traditional and modern may not work out very well. House is one object and it should stay in the same style. Advantage of using aluminum windows is that vertical bars between glass partitions are very narrow. So you will have a lighter structure look. Wooden windows definitely will have thicker bars, depends on windows profile and producer but can be about 5 cm wide. We have developed one project in Chamonix France. We had long discussions, because house was facing Mont Blanc mountain and owners wanted to see most of it. In the end we went after wooden frame windows, and we were happy with the result. Here is the photo: Also you can find more photos of aluminum and wooden windows in my article about different window types.

Galvanised is steel dipped in zinc which can and eventually will have rust break through, as an alternative you can have zinc or stainless steel guttering ( https://www.metal-guttering.co.uk/zinc-guttering-jtak4 ) or a cheaper option if you like powder coated would be a polyester coated aluminium like this: http://www.marleyalutec.co.uk/products/downpipes-and-hoppers/tudor-circular-downpipes/ . Personally I would not recommend bare aluminium as even if it is marine grade it will dicolour with a white powdery surface and then begin to corrode, it will also degrade electrolytically in the presence of other metals especially copper or lead. With Zinc or copper guttering it is important to use the correct fasteners to avoid electrolytic action which will corrode the metal, if you live near to the coast and have salt air, zinc is not recommended but copper is, best of all is stainless steel which has been passivated (cleaned chemically to remove all contaminants from the surface). A link to understand electrolysis: http://www.bergerbp.com/blog/gutters-galvanic-corrosion

Are the faces aluminium also? That would not be the norm. Usually the walnut finish is over a composite board, basically laminate. If so, then coat with a good quality primer such as Zinsser 1-2-3 - the blue water based one. Then you can paint straight over the top. You're probably best to go with a satinwood if you want a soft sheen or any gloss.

Hi Tani, Yes, you can do secret gutters with a GRP flat roof system. I have designed one for a project about to start on site later this month. Some screen prints of my details below. Basically, I'm proposing to extend the flat roof joist out so it oversails the wall by about 300mm and have the ends of each joist chopped out to create a recess at the end. This recess is lined out with plywood and timber blocking and the GRP roof membrane is then dressed down and sealed up etc. Your architect / technologist / designer should be able to show this on their large scale section drawing as shown below. We are going to tweak the detail a bit so the vertical sides of the gutter are sloped and not at tight angles but apart from that what is shown below is how it should be built I think. You need to make sure the secret gutter is large enough for the volume of water it will drain away. You will also need a special hopper detail for the rainwater pipe to connect into and this will probably create a step out. I also suggest you use a good quality GRP roof manufacturer and approved installers, such as Polyroof. They have good technical support and worth speaking to them for advice also. It's worth spending a bit of time on this now to get it right and priced up properly before any work starts on site. Hope you get something sorted. I'll be posting some as built photos on here in the near future.