Hi Cap. John,
You've hit on one of the problems of hooking these pipes up. Typically they aren't turn-key kits that are ready to bolt on. You have to get all the parts and hope you know someone like DH that can help you out with a starting header length...and in many cases you need pay a professional welder or have access(and skill) to your own heli-arc setup(I've noticed DH uses mild steel headers, so in that case you wouldn't need the fancy welder).
For the Taurus, MACS(
www.macsproducts.com) has a Sachs header that will fit. For other engines, if you don't fit one of the ones available, you'll have to ask the people that carry them to measure the ones available to find a fit(I bugged the heck out of Dave at DA to try and find a KS one for the Taurus, but I could only find a close fit). KS makes quite a few header adapters. Desert Aircraft(
www.desertaircraft.com) carries them in the U.S. and you can see a partial list on their site. MACS is also a good source of headers even if you don't use their pipes.
Here's one more point to consider. MACS uses a one piece header that curves and runs back several inches. They sell them with 3 different radii. KS does make a one piece header, but their typical setup uses an exhaust flange with a variety of curved and straight sections, and flex tubing, you can buy to make up a header that fits your application. This makes it much more difficult, but gives you total flexibility in your installation. Look at DH's site for examples.