Went to a cheap vinyl rain suit after spending a pile of money on a rain jacket that was supposed to breath and didn't. Like Plink says, any of 'em will get hot if you're running around.
I started out with semi-cheap camping rain gear and cooked in it, because it does not breath

My own sweat that built up under the rubber made me more wet than I would have been from the rain :'(
So far, I really like the German made, French Army goretex -- they were made for this stuff and will work up at the cottage, camping, fishing, etc.
In other words, I totally agree with Hungry... but went a little further, trying to identify the "best" made military surplus
As for the Tru-Spec, H2O Proof ECWCS stuff... I was considering it in multicam but decided against it, because it sounded far too warm:
ECWCS is an abbreviation for:
Extended Cold Weather Clothing System
And I wanted something that could be used in the summer too.
I will investigate this "stealth" stuff, but it sounds like I would end up wearing wet clothing... and I have been looking at ways of making things accessible by ensuring that they can be placed over the rain gear (winter gear, or whatever else).
For example... I went with this so I could put my "duty" belt over anything:
Modular Padded Belt System
http://www.highspeedgearinc.com/proddetail.asp?prod=HSG-SGPB
DISCLAIMER: I am not providing any advice (because I am somewhat stupid), but am simply sharing my solution(s) to the same issue/challenge and my solution(s) are subject to change in the future.
NOTE: The London Bridge Trading Co. vest has "duty" belt loops, so that vest can also be placed over rain gear and be fitted with a "duty" belt using its belt loops or the modular padded belt system noted above can still be used
