I've always used the alcohol method for detecting leaks. Turn them inside out and give them a spray. The dark spots that show up are the areas that leak.

As far as "quality" brands I'm sure there are a bunch but I'm firmly in the Simms camp when it comes to waders. I got a pair of blackfoots that are over 8 years old that I've had to fix pin hole leaks in twice. I'll admit I've not used these waders very "hard" over the last 4 years (I've only been getting 10 - 14 days per year of wader fishing in during this period).

But I've never been disappointed in the quality or customer service from Simms. I just purchased a pair of G3's that are going to get used hard starting with my retirement next year. The decision to go with this brand and model was largely based on my very favorable experience with the Blackfoots.

Good luck with the repair!