Which nails/Screw to prevent rust staining on featheredge

I am Featheredge Boarding a Summerhouse which I am planning to paint a cream colour with Masonry Paint.

Which nails / screws should I use to fix the Boarding to prevent brown rust staining.

Will Galvainsed Round Wire be ok, or do I need Stainless Steel?

Any advice appreciated.

Thanks.

why are you using masonry paint on timber? It wont adhere very well.

Nails. Screws will look pants.
Galvanised will be fine, use stainless if you don't mind the extra expense. The paint will protect the nailhead anyway.

Also: What Thermo said.

If you want to use masonry paint, consider using fibre cement cladding boards. Or use a timber friendly paint.

Some interesting colours here:
http://www.holkham.co.uk/linseedpaints/faqs.html