Cordura can be sewn on a regular domestic household machine. Besides the right size & type of sharp needle (and a new one installed before use), I always use a lighter weight fabric and a good 100% polyester thread (better than even the all time favorite cotton for synthetics). It is the motor's power or strength that pushes the needle through the layers of fabric no matter what type of sewing machine it is. For water resistance, I would look into the the Scotchgard™ Protector Repellent finish here and similar brands offered out there after completing the bag or whatever it is construction. Then you won't be limited to just Cordura or nylon. Of course the inverted upside down plastic bag tied over the bag itself would do in a pinch-I usually do this if caught out in the rain and have bags to completely protect from water damage, check for holes though.

http://solutions.3m.com/wps/portal/3M/en_US/Scotchgard/Home/Applications/Apparel/Manufacturer/Types/Repellent/

One of the nicest things I have learned in my time at the CA garment district is using the simplest possible solutions or production in mass marketing all sorts of samples I had to churn out quickly after the presentation of sketches and pattern drafting. Since I had to sew all types of products (not just one type like a bag) usually women's and children's clothes, I used many things usually found around a typical house or purchased inexpensively at most any store in the workrooms in order to keep costs down. So I still do this at home now with the exception of an industrial single needle sewing machine (cannot fit one in the space I occupy at present).