I have a 88 XJ and installed the one piece dealer pan gasket a while back, it worked great! I think I paid $45 for it but it worth the price.
I asked my dealer mechanic for tips to install, he told me to pull the pan, scrape the block and pan clean then run a small bead of RTV on the block. Then use the pan bolts and install only the gasket to the block.
Then let the gasket sit there for a few hours, you are using the RTV as a glue to hold the gasket to the block not as belt & suspenders solution for the gasket. The gasket will seal fine by itself so additional RTV is not necessary. After the time has passed then pull out ALL the pan bolts and install the pan. It worked well for me.
I had a pain getting the pan off and ended up bending the lip. With the hours I spend on the block cleaning the old gasket off I decided I was money a head to get a new oil pan from the dealer. I was doing this job at a shop and renting a lift at $4/hour, it was adding up.
You will need:
* A tube of RTV. Even if you don't follow my installation suggestion for the one piece gasket, you have to fill some holes in the timing chain cover. The 4 piece gasket has nipples that filled the holes but not with the one piece gasket.
* A "good" gasket scraper. a putty knife will make your life hell so go to sears and buy the $10 scraper.
* A troque wrench, torque the bolts to the published values, I have had no leads.
* Rubbing Alcohol, to wipe down the mating surfaces for the gasket.
Also if you have the pan off you might as well change the oil pump 'while you are there".