I also recommend driving the Jeep, but I do recommend you do a complete maintenance to it beforehand; you really do not know what the previous owner did or did not do in this department, so better to be sure. You can also (as already mentioned) look for improved parts while you are at it. For example, if you are going to change the ignition system (plugs, cables, rotor, cap) as you would in a regular tune up, you may want to look at a Performance Distributor's setup and change the coil while you are at it (depending on your mileage, it may be due for a change anyway), and gain a better ignition system in the process.
I would also replace all the oils and liquids (engine oil, transmission oil - recommend Redline MT90 here, transfer case oil, differential oil, brake flush, coolant flush, etc.) to be sure that they are up to par, as well as changing the belt. I dont know how many miles your Jeep has, but depending on this, it may need a new cat (if so, it would be a good time to upgrade to a high flow cat).
As mentioned before, check all U-Joints on your driveline, and if necessary, replace them (they are not so expensive, and you can upgrade here as well; you can also choose between greasable and sealed, and of you ask about which is better, you are likely to stirr up a debate here, so I recommend you read about both and make up your own decision).
After this, you can start doing upgrades as you see fit. There are a couple of projects here that you can follow (as you mentioned, Moz's build is one of them, but there are many others; you can see mine
here and see how it has evolved over the past 3 years if you want) and get some ideas as to what you want your rig to end up.
I think you do have asomehting clear and this will save you many headaches; you are going straight for what you want, and not cheaping out. This will save you from buying what you can afford at the moment and then having to replace that just because you did not buy what you wanted in the first place, which is another way to say, it's better sometimes to wait, save up, and get what you really want in the first place.
Felipe