Our main advice is to work with a local solutions provider where possible, for knowledgeable, trained installation and maintenance support. You want a provider who has links to the manufacturer of the products used.
Although we suggest working with a local solutions provider, it is also useful to gain a basic understanding of products and their design independent of a supplier. The following links are provided to manufacturer web sites. All of these manufacturers work with a large network of dealers around the world (local solutions providers) to sell and distribute products though they can and do sell directly through their web sites.