Before I bought my rig (34J) I had similar questions. I was able to do a google image search to find some dealers will post a picture of the cargo capacity sticker. Here is a link for the 29M it looks like it can carry about 2200 pounds. I'm sure other owners on here could tell you what theirs say as well.
Remember that ANYTHING you bring into your rig counts against this weight limit.
I don't have the washer/dryer so cannot help there.
Hurricane and Windsport are virtually the same, the different brand names allow dealers in close proximity to each sell the similar product. Floor plans are the same. There are very minor differences in color options and the headlights look different. Our preference was the Winsport.
We have had ours for almost a year and have a few friends that have owned them longer. We are happy with our purchase and haven't had any major issues to report. We did buy a Camper's Edge warranty for a bit more peace of mind but haven't needed it since we are still under warranty. Our local dealer (we bought from a different one out of state) has been fantastic with even the smallest fit and finish issues and helped with a couple other issues that were covered under the warranty. As you mentioned these are complicated machines with many 3rd party components bundled together so you have to reasonably assume some things will go wrong over time. As long as you have a good understanding for how things work so you don't do any damage yourself, and you have a good dealer to help you with service, I think you'll be very happy with your purchase.