After looking over the ebay selecton of catch cans I decided that the rectangular "greddy style" can seems the best.
I have looked at a bunch of internet sites and I just wasn't happy with how people made their internal tube and what they used for baffling.
I chose it because it can easily be opened to add baffling, it has a drain, it has a nice sight hole for checking how much oil has accumilated, etc.
I got mine from "fastwayracer" on ebay for something like $32 shipped. After about $30 they switch from a round can to this style can.
While the basic can is nice they didn't go the extra mile and de-burr all of the cnc work and the can is not baffled internally so it needs some work but isn't anything you can't quickly clean up with a utility knife.
For baffling I looked into this a bit and decided that "stainless scrubbing pads" are the best bet. I got them for $3.99 at target in the kitchen scrubber section. I used both scrubbers that came in the pack and decided to stretch them length wise and put them in side by side.
This is NOT STEEL WOOL. Steel wool is not what you want for this because the fibers can separate and get into your engine. The scrubbers are much larger and hold together well so that they avoid that serious problem.
The hardest thing to figure out is how to make sure that the air will go through the baffling. To accomplish this I ran a 3/8" NPT tap into the existing threads from the inside of the top cover. I only tapped it about a turn or two so I could thread into it. A perfect seal is not really required so don't worry about it.
I then used a 3/8" NPT to Inverted Flare adapter and connected to a 3/8" brake/fuel line from the parts store ($5). It only has to thread in a little and remember it is sharing the threads from the other side so don't go too far.... The line is only 3/8 but it will easily outflow the PCV valve so I am not concerned about it.
I bent the tube into about a 45 degree angle being careful to make the bend gradual enough so that the tube didn't flatten and collapse the tube at any point in the bend.
I then cut it to be just above the bottom of where the oil level starts to show on the indicator and added relief notches to the tube with a file. It is important to have the notches so that when the oil reaches the bottom of the tube (and then the lower notches) it doesn't plug the tube. My last notch is even with the top of the indicator tube so I will have to keep an eye on it and it will be important not to let it completely fill...
Next I added a breather filter from Autozone's PCV section to make sure that the stainless scrubbers can't get sucked out of the case (it isn't likely so this is optional but it was only a $2 filter and it is made to be a PCV filter so it seems like a nice addition to me) The filter does have a top and bottom side so make sure to install it in the correct orientation if you use one.
When connecting the can the suction side should be connected to port opposite the internal tube.