Join Date: Sep 2011
Location: Germany- but not German =D
Welcome to the forum!
Have you looked in to slightly heavier breeds, or crosses?
I can't give you any info about a western saddle as I ride english; it's always important to make sure you get a saddle that naturally fits your horse, but fits you too for comfort and weight distribution.
A lot of time it is not only weight, but how people ride. If you are a heavier beginner rider you may unintentionally hurt your horses' back, where as if you have more experience you can balace yourself better.
My advice would be to post in some of the weight loss threads on here, if that is your ultimate goal! Everyone supports each other, and I am sure they will be more than happy to help you find a suitable horse and breed and saddle etc :)