Lots of discussion out here on 87 or 89 issue. I have used both and notice a slight difference in performance with the lower octane. Some out here say they don't notice any difference so its really up to you. Both seem to work fine & I've had my Jeep now for about 16 months.
I've run both 87 and 89 and have had no issues and noticed no difference between the two, but I also don't tow and it's usually just myself and my gf in the jeep at any given time.
I switched to synthetic but I don't think you'll notice any major difference as long as you maintain good oil change intervals. I like the longer intervals of the synthetic but with the amount I drive I doubt i'll ever actually notice any real benefit from the synthetic, but it is a minor cost increase and gives me peace of mind.
2012 Stone White Overland Hemi ~ Altitude grill and brow ~ SRT8 reps ~ Falken Rocky Mountain ATS ~ Mopar pedals ~ SRT8 side lettering ~ 20% tint all around ~ Volant CAI ~ HF Tune