Cordura Nylon is waterproof, windproof and breathable. It is available in many weights, written as "denier".
It can also be purchased with a wicking layer, waterproof liner or almost any number of other combinations. It is not a very light fabric, so if you want a mesh type wall that is suitable for summer camping in the southern states, this is not a good choice.
A silicon impregnated or coated nylon will be very light, more breathable and quite water resistant. It does not hold up well to UV exposure over the long term and can be quite expensive unless purchased in bulk or on a wholesale account. Overall, however, it is a tantastic material used in making high end tents by companies like Hilleberg:
http://us.hilleberg.com/EN/our-tents/materials.php
Gore-Tex fabrics are quite difficult to come by, as W.L Gore only sells to approved manufacturers and they also guarantee the final products from those manufacturers. Some entry level fabrics can be found online, but the Pro level fabrics are unobtanium.
There are similar products made by other companies, some of which are more readily available, however with "breathable waterproof gear" a multi-billion dollar industry, many fabrics are proprietary and fall in the category above
Clothing and packs/bags, typically work on a three layer system, that is an outer water resistant layer, an inner PTFE based breathable layer, and an inner mesh type fabric to protect the PTFE/Teflon, which is quite fragile if left exposed.
A heavy canvas or duck cloth was quite popular in the past for tent manufacturing and can be easily obtained in almost all grades and price points. It is mostly used in cold weather applications and where weight is not as much of a concern, Kirkhams, Snow Trekker, etc
With SO much production of clothing and gear being moved to China, finding domestic, reliable and quality sources for fabrics may be a challenge in and of itself.
Good luck.
EDIT: an industrial hook and loop material (Dual Lock) can be an excellent attachment product, but I am unsure of the water proofness. I would also look at 3M's double faced tapes, some of which are amazingly strong, so be careful. Testing shows the substrate failing before the tape, so once it's on (with certain products) it's not coming back off easily.
EDIT 2: Check out WeatherMax fabric for something similar to Sunbrella, but better IMO. I think it is made in South Carolina. Cordura is also available in many weights, with something like 1000 Denier being very heavy for a tough gear bag, while a 300 denier, is light enough to make a pair of trousers.