I can answer your Mishimoto questions as I have the top of the line Mishimoto OCC
The filter is sinthered bronze which serves as an additional barrier between the oil/liquid particles suspended in the gaseous compound coming out of the PCV. This same type of filter is used on some of the better water/air filters attached to air compressors and paint sprayers, or in my case, abrasive blaster. I've had my Mishimoto for over a year, and nothing has clogged up yet. The mishimoto also uses a baffle that has holes drilled in it
Also, I've found no need for a check valve, even though I purchased one, as the outlet from the OCC to the intake is bone dry. (I use clear hoses to monitor the amount of iol in both hoses.
Depending on the radii of the bends and the finish of the bracket, there should be no cause for alarm when it comes to fatigue cracking. I'm assuming Mishimoto will be using stainless steel. When you get your mishimoto, check out the edges. If they are chamfered and look like they've been through a vibratory hone (which my bracket was), there should not be any reason to worry about fatigue cracking. Fatigue cracking comes from sharp edges, and surfaces that are not deburred. These create stress risers, which multiply the stresses on the bracket. Removing these stress concentrations will improve the fatigue life of any part.
My two cents.
I would rather get the OCC I purchased, for about $160, purchase the hose for another $25.00 and make my own. I think the colored hose is fine, but you can't see how well the system is working. Plus the can size is really small, compared to the one I purchased. You can get a replacement PCV hose for $18.00 from Rockauto, so you end up with a DIY system that is as good or better that what Mishimoto will be offering. Like I said my 2 cents.