I don't recall ever not having a build going for more then a month in my shop. I use a lot of wood every year so I have used most of the wood supply stores. For the most part I have never found one suppliers wood any better then others. The cutting yes but not the quality of the wood itself. Some places like Lone Star must use beavers to cut the wood and I have to straighten up the edges, once in a while some wood may have some warp to it but for the most part it is all pretty much the same, good quality. Some of the best I have used is from National but it is just the edges being straighter. I like BAUSA myself and like dealing with them but there prices are out of line with my pockets.
Weight will vary but it is with all distributors, they buy in bulk and just cut to size.
I have always bought contest grade and been happy with it.
These days I just buy planks and cut it to size myself, I'm blessed with a very good wood shop/club. I do cut my sheeting over size and run it all through our over head micro sander so it's all the same size.
These days price means more to me then with what distributor I use. Some places I have used over the years have gone nuts with there pricing. I do a lot of shopping around these days and am very surprised with the price difference.
10 planks of 4 inch wood will do a lot of building if you have a good recut saw. I'm very lucky to have one.