I have the much maligned Wake Designs racks. They don't slip if you tighten them enough. There are two mount sizes, you want the smaller size mount, the bar is 1.625" in dia. You can also drill and tap the quick release mount for a slightly bigger set screw. I just replaced it with a black 14/20 hex head machine screw that I can tighten with a box wrench instead of an allen wrench. A 5/16" or so (8mm) is the next size up, and you'd be able to use a bigger allen wrench for the bigger hidden set screw. It does tend to gall the mating surface of the quick mount so they are hard to remove. They don't rattle so I quit trying to take them off!
The reason I mention this is because they are OK racks once you tighten them up. You can get them dirt cheap on Ebay.
They do tend to chip the tower bars due to the clamp style mounting, and can ding your board edges if you (or your kid) pulls the board down into the boat instead of lifting it out of the racks first.
Mako makes some nice racks, they have removeable plastic sleeves that you can get in many sizes. I may ditch my wakedesigns and upgrade to Mako this year!
1 3/4 racks will usually fit if you use a thin strip of bicycle inner tube to shim it.
I would recommend Ebay first, you may find a deal there. I bought one rack for 50$, then paid retail for the second. Couldn't ride around with one rack!
It's hard to find white ones if that's what you want. Better to special order and pay big bucks. You may get lucky though.
I bought some really nice Bose 151 (speaker) mounting brackets from RynoGear. He is still in business but sells motorcycle parts. He was reasonable (100$/pr) and they are top quality. They will fit just about any speaker if you don't mind drilling holes. Don't know if he still sells them. If you email him, tell him Pete with the Epic sent you. He had pictures of my boat on his site for a while.
http://www.ryno-gear.com
