Steve,
I suggest that you post this same question on
http://www.kiteforum.com.
I have a Naish Shift Bar with 5 lines and a Windwing 4 line bar. You can have both for free. Both of these bars are safe, it is a good idea to set up both of your kites with a 5th line as it kills the power when you drop them to the 5th line. It is not hard to setup most "C" kites with a 5th line. You just need to attach a single line to the middle of the leading edge. Hopefully the 21M OR will have a pump leash that you can attach it to.
Most of the local kiters have migrated to the new bow or SLE style of kites to deal with the gusty conditions around here.
Kenny