Jonmac81,
I think most of the things of importance have been mentioned. The cam sprocket problem is the most concern. To determine if they have been welded, you need to pop off the valve covers, front and back, and look for the welds between the sprockets and the cam shaft. If you look around here, you will easily find photos of what it should look like and where to look, or you can check over on V8SHO.com for the same.
As has been noted above, at 200k, likely it has already been done, but you do want to check anyway. Popping the valve covers is not a major task. Be careful with the gaskets when you do it, though, as you will want to reuse them.
Mine is currently somewhere north of 190k and as mentioned by others, it still runs like a top. Once the cams are taken care of, the rest of the car is just normal maintenance. Those rear brake lines do need watching. I replaced mine for the first time about 2000 miles ago. The transmission eventually needs rebuilding as it wears out, and if the car is pushed hard from stoplights and such, that likely makes it go faster. As yet mine has had no problems at all, but others have had to rework theirs much sooner. If yours has 200k on it and seems to be shifting well, you likely have one that has not been abused, so there could still be a good amount of time before it needs to be rebuilt.
At that distance, you might also find that the struts are starting to get old. Would not hurt to check out all the various suspension components and see what might be worn out and not yet replaced by the prior owner.
Best of luck with your new toy.
pax, smn