I'm trying to determine the proper length for my driveshaft. It is 34 from fixed yoke to fixed yoke. Which driveshaft do I get?

• I'm looking at getting the Extreme Duty rear Driveshaft ( #8581 ) but my size isn't listed. for the custom length option fitment
• I'm looking to off-road, I was wondering if this shaft can handle well in sand dunning, rock crawling and muddy terrains general
• what rear u joint do these come with general