I wouldn't touch a rhinegold rug unless your horse is a very odd shape, I had a 6'3 which is the size all my other rugs are, it was about 6 inches too long in the body BUT didn't even come to the bottom of her sides in depth!!! lol and she's a tb x and isn't even overweight!!!!!
Weatherbeeta have always been a good fit and last ok for that price rug. I have my rambos and fals that have lasted now between 10 and 14 years!! So I suppose alot of it is you get what you pay for!!
Oh forgot to say, for an average priced rug the amigo 1200D I've found to be a very good rug, stood up to everything, keeps the water out and because its 1200 denier its strong. I wouldn't touch the 600d ones though as they don't take much to rip them.