Yeah, unfortunately the rear bumper step pad will not fit the base Yukon bumper properly, it will stick out about an inch. So for it to look right you have to replace the whole rear bumper assembly which is the bumper cover + step pad + chrome trim + hitch cover. It's not cheap, but if you're patient and wait for deals here, on ebay, and craigslist you can accumulate all the parts for around $500 and then have them painted. The actual bumper swap takes no more than half an hour.
OEM chrome handles you can get as a package for around $100 but it can get a little pricey to have them installed ... but if you're good with your hands there's a tutorial I can link you to where it shows you how to take off the door panels to do the switch.
Escalade mirrors in good condition run around $300 a set depending on which version. If you're going to change the handles it's advisable to have both done at the same time so that you don't have to have the door panels taken off twice.
The door trim is also rather pricey at the dealer and again you have to have those painted. Sometimes they become available here when folks demold their trucks, and I hear a place called Nordstrom Auto sometimes have them at a good price.
Hope that helps a little.
Let's see you truck Steve.