Let me just refine what Jingles said. It's correct, just want to clarify.
Now, I am a sound production company, and I typically run my DMX down my 200-foot whip. That's my snake that goes from my 56-channel stage box and my console's front end. So, chances are, you can use a spare INPUT channel on your 100-foot snake, or else(and I recommend) run a sepparate 120-ohm XLR cable for your DMX-512 signalling. I'm ordering a 200-foot cable to match my cabling, which tyically consists of the 200-foot whip, 2 200-foot Cat5's, 200-foot BNC for video and soon that 200-foot for DMX.
So, go from your controller to your FIRST LED ParCan64 using that 100-foot DMX cable you make. In fact, what you might want to do is run that to the REAR truss. Also, maybe make a cable that runs down from the rear truss to the ground, then attach that to your long run. Why? Maintenance. Then, take a much shorter cable, say anywhere from 3-10 feet long to from one ParCan64 to the next. They have DMX pass-thru connections. It's easy, go DMX IN to the INPUT and then pass it along using the DMX OUT. Simple. Repeat until you run out of lights on that back truss, then take a 20-foot cable and go from the back truss to the front truss, making sure to leave a little slack, but to also clean it up as much as possible. Repeat the daisy-chaining until you're out of lights. Then, insert a DMX terminator in the outstanding DMX OUT on the last fixture. Build your own, it's cheap and easy. You may not need it, but I recommend you do this anyways, it's highly recommend it. I personally built mine and I am going to build a few more just in case.
Now, as far as the DMX Operator is concerned, take Jingle's advice and go for the Pro. Now, I can program movers using my lowly DMX Operator, and in fact, I prefer this for one simple reason: Since I have them on different "channel bank" switches, I have them assigned to the same faders, so I can use one fader to change color or gobo or other things. Handy function. But, in my case, it's knowing how to use what you've got. But even if you just want to do the Par64's, you can save money going with the [URL=DMX Operator]http://www.elationlighting.com/product.asp?ProductIDNumber=1091&cat=Controllers%20Distributed%20By%20American%20DJ[/URL]
In regards to the Pro LED fixtures, that's what I am going to buy 8 of for now when money allows. And when money allows again, another 8. I might have to go 4 and 4(and 4 and 4). The Pro's have higher output. For yours, you can get by with the regular LED Par64's since you're in a fixed location and not worried about mobile applications.
Sorry to go on and on. I'm detailed oriented. I walked off a job this week because it was a certain special type of "cluster", if you get my drift. I hate inefficient and disorganized. They are taking 2 days to do what could be done in 6 hours with fewer guys. Time for them to learn what being professional means. I earned the same money in 2 hours going to another job site. Beats 4 days of dealing with idiots.