I agree with Bill but check the price with EZ, you will find its in line. Then look at the different holders and make up your mind.
I try hard not to say one is better than the other but just what I use and why. I can say out of what I have tried the SyderLoks are what fits my needs the best, if not it wouldn't be on my boat. Will that change, not sure, time will tell.
The Millennium seats are awesome as well, I prefer the Saltwater version.
Good luck and have fun rigging your boat.