The RRS and Kirk plates are the best for all-purpose use, but if you only plan to use them while doing panos, cheaper ones like Sunwayfoto (even the one you mentioned) should be fine. The important point of differentiation is you don't want a cheap one if you hang your camera off it or you need precision.
I have no experience with the Dolica you mentioned, but your tripod should still feel pretty sturdy even when the camera is tilted 90 degrees. If that is not the case, even with a 5DII and 200mm, then maybe you should consider a sturdier tripod first?
The tripod its still sturdy, its just on uneven terrain and stuff. My real question is what clamp should I get to replace my Dolica one to fit acra type stuff? Would this one be a good choice? http://www.amazon.com/SUNWAYFOTO-DDC-60-Compatible-inches-Sunway/dp/B004ED815A/ref=sr_1_10?s=electronics&ie=UTF8&qid=1391376207&sr=1-10&keywords=arca+clamp
While I have no problem suggesting a cheap L bracket, I wouldn't advise a cheap clamp. That's the part that will hold the camera equipment securely, and if the mechanism isn't up to par, then your camera might slide and even fall.
Given the ridge on the ball-head post in your picture (its similar to my Z1), the following clamps will at least work:
RRS B2-Pro II
Kirk SQRC-Arca might work if the hole is not threaded
Check a couple of things though- does yours use a Metric 6 screw or a 1/4"-20? Also, is the inside of your Dolica clamp threaded?
The clamp is not threaded, and I think it is M6 because it has many more threads then my tripod screw for my camera
Okay, then the above 3 options will work.
Also, Wimberley (tripodhead.com) sells scratched but fully functional C-12 clamps at a discount.
I think they are $ 63.