Any suggestions on better gear? Do I need to watch the height and width? Do you have to be careful of the stance between the front and rear heights?
What model?
I go with Ken on replacing the firewall. You could epoxy the piece and a plate 1/2" wider behind it to reenforce it, but that adds weight and will never be as good as new.
The height on the new gear is unimportant as long as the prop clears the ground (including bounces). What you don't want is a jacked up butt or nose. DuBro has replacement struts that may be better than your original. Don't drill out the firewall until you get the gear in case the mount is different. Bendy gear is not necessarily a bad thing as wire bending is easier than woodwork and finishing.