Just about everybody sells ACC carpet, so it will likely be the same stuff anywhere you get it. Shop for the lowest price plus shipping. Some places gouge you on shipping. Rock auto was the cheapest I found when I did mine earlier in the year. Lots of tips and opinions in threads here. I found them very helpful.
I liked the mass backing option. Helps the carpet hold its shape.
I also used the dynamat clone from Amazon, think it was Noico. Was about 1/3 of the price of dynamat. I really quieted the car down inside a lot. Just depends on time & $$ you have available for the job.