Sheldon, just a bit of advice I’ve been given and whole heartedly agree with.
Buy from our local shops, its a good thing to support them or they may not be around when you really need them.
Can you find things cheaper online?
Sure, but supporting the local community is always better. Not all my gear is new, hell very little of it is. But when it came time to get my new flywheel/clutch, piston stop, clutch tool, and Mychron I used the local guys. Like I said, it may be a little more expensive but in the long run its worth it when you have an emergency to deal with or need some local support.
Just my .02. I haven’t had any experience with the sites you listed.