Maybe the best way to see it is: Upgrade the D30 (cheapest option) and if it bends or breaks too much, upgrade to D60s!
Overall, the D30 seems to have a very good chance of working out well for my tire size (33s) and type of wheeling (mid level rocks trails and scenic trips). I'll be keeping the 4.56 gears too, so one more point in favor of the D30.
Thanks for the comments.