There are so many alternatives out there for headers these days.
From a perspective I'd rank things this way
PEM'* IMO are not worth the time to bolt them on. Typically only the mouth was opened. Yet the restriction of the front manifold is the neck. If you can't address the necking issue, you are doing very little for performance.
PLog (Front only): Great alternative to headers. It'* becoming common for them to crack as they are welded inside and then ground down. A good suggestion is to have them rewelded on the outside for bulletproof operation. This can be bolted on easily since it replaces the stock manifold and uses all the same locations and hardware.
Headers: I'm in a unique place where I've had experience with and installed most brands of headers. SLP'*" I have them and like them. Good fitment and good O2 sensor location. Kevin had trouble with the crossover and is the only person I've heard to have that issue. Most find the flex ticks, replacing that upfront or wrapping it with header wrap is a cure. Slip fit to put together. TOGS: being that they bolt up with exhaust donuts and flanges, many times they leak, IMO the donut is a partial restriction. Install is a bit of a pain to balance all the donuts, bolts etc, sealing can be challenging, O2 location is not in a good place for 92-96 H bodies. It is common for me to see these smeared with a full tube of RTV to seal them because they were installed by a person who didn't tighten the connections equally at the same time. The flanges for the connections are bulky and can get in the way when doing a trans swap etc.
PaceSettes: Many have had lots of success with these. For a budget header they do the job well. Research the modifications, clamps, welding or gaskets you should get and you'll be pleased with the cost and performance. These bolt up like TOGS with flanges and donuts.
OBX: I've never installed them, have heard of fitment issues though.
SSAutochrome: SLP knock off'* at a great price. Overall they seem to be good quality and like the Pacesetters, research is the key. These headers don't come with clamps.
With any header on an H body (our cars) you will require some welding. They were designed and are originally marketed for the W body. There are pieces that bolt right up to the factory catback on the W body. H does not have that flange/split in the exhaust. Some cutting/welding or clamping is required. A single reducer is usually all it takes to adapt from the header downpipe to the factory exhaust.
Overall, I'd probably suggest the SSAutochrome headers for price and fitment. $300 brand new at their website.
00 Regal GS: All kinds of cool stuff.