Here's what I gather on the most reliable cars of this generation:
I should get a 2003-2006, as many trouble issues have been fixed by the end of the run. (and that will have the 6-speed?)

I am now keeping my eye out for a XK I might want to buy.
I want a coupe so that narrows my choices. I also want an XKR, but a question I have is:
the XK8 has 290 hp and is NA. Is that engine better from a reliability standpoint? compaired to the supercharged XKR at 390 hp?

Is the 6-speed tranny more bulletproof than the 5 speed?

I really am somewhat fearfull of costly repairs as I don't turn a wrench well myself.

Any advice is welcome

 

Also, Are the suspensions the same across all the '96-'06 XKs?
It seems like the wheel gap varies in some photos. (Are aftermarket suspensions prevalent) I just want a stock setup.

 

Your in the right spot for information. My best advise is to learn how to navigate and search the forums here. This topic has been discussed many times and you'll find knowledgeable as well as enthusiasts folks have made recommendations.

Read the Sticky DYI , watch some of the 'how-tos'
Use the search on the right, under the page count to find answers to questions,
Certainly folks here will respond but I spend 5-6 months reading before my first post! Most my questions were already answered.

As to which car.. I have a 02 XKR (47k)... Very happy but I've also done maint and preventive maint myself.