need some suggestions (24" or 26" muni)

I am looking at getting a 24" or 26" nimbus muni from or hayneedle…

I am 6’ 3" and weigh 210 lbs (age 38 with one knee surgery). I am wanting to ride trails around Austin, Texas. Nothing too crazy. I would also like to hop around and try to learn some tricks… so I think I should get a 24". Any suggestions… based on my height is there going to be much difference? Also, do I want longer or shorter crank arms?