Catalytic Converter

I originally posted this in the general S-10 forum but have not received any replies....
I have a '95 S10 4x4 with the 4.3 Z code engine (TBI) and live in Virginia where we have to pass emissions every two years doing the dynomometer test. I need to replace my catalytic converter because the one I put on almost 2 years ago seems to not be a 3 way cat, doesn't take care of NOx, but at least I got it for free. I am looking at buying an after market cat but don't want to buy one and not pass emissions. Has anyone here installed an after market cat and what brand did you buy? I was looking at Eastern Catalytic, Megaflow, CatCo, and Walker. While each company claims I will pass emissions testing with their cat the price differences between them is significant, making me question if some will work. Thanks for the help.

A good parts place can get a walker OEM type direct fit cat.
That will fit and work right with no welding on.
Or a good muffler can weld on a universal cat.
But as always good tune up is the key on passing emissions and keeping the cat working good.

I already have a universal cat on the truck. Just before inspection and emissions testing two years ago I had to replace everything after the catalytic converter because of rust. Most of the chevy's around '95 used a triangular flange to connect the cat and muffler, where three bolts tread into the flange on the cat side. All three of these bolts broke despite my best efforts. In drilling out the studs in the flange I must have banged on it enough to fracture the cat. It passed emissions that year but only lasted another month until breaking into three parts. A friend had a brand new universal cat he wasn't going to use so we bought all the parts required to make it fit. Two years later I find out this cat will not reduce NOx emissions so I need a new cat. With my current setup I can easily put in a universal cat and there are plenty of companies that make them but I don't know which to go with. It doesn't look like Walker will work because they only make one 18" long and my exhaust will only allow up to a 16" long cat. Has anyone here ever used Eastern Catalytic, Megaflow, or CatCo? Thanks again for the help.

An update for anyone having to replace their catalytic converter... I ended up buying a CatCo universal from Summit Racing, only $61. On Monday I installed the cat, now I remember why I don't like exhaust work, and passed the emissions test on Friday with no problems.