sprint. run. jog: help me pick out a shoe

My lower back hurts. I'm prone to lower back pain but this time it hurts. Yesterday, I went on a run and had to cut it short (5 miles) because I felt a lot of uncomfortable pressure. This morning I still felt funny (plus I woke up late) so I didn't run.

I'm a very impatient and stubborn person and when something hurts I usually ignore it and maintain my schedule, but this pain is really starting to worry me / freak me out. (I'm also have a worried and paranoid personality, and it's not helping)

I really enjoyed my trail run this weekend and figured if I was going to do it again I need proper shoes. I found these mizunos online and can't decide on the color. What do you think?

Item # 045407