Hey John,
Funny you should bring this up. I was conversing off line with someone about roll bars and also talking to a racing buddy in the pub about them.
In short, I prefer to do my track chassis tuning and setup without anti-roll bars. I think if you get your springs and shocks right then they will not be needed, at least for the majority of the setup. The roll bar is nothing more than a spring that adds it's rate in when stressed, i.e., under cornering. If your springs and shocks are dialed in already then there is a good chance they won't be necessary under most circumstances.
I feel that there is some misconception that if your car doesn't have an anti-roll bar then it won't handle well. There might be some truth to this for a street car. After all, if it is sprung so that it'll handle well then it might be sprung too harshly for street use for some tastes. The roll bar provides additional spring when needed, under cornering, but not while cruising. So, the car can be softer sprung for a better ride and still corner decently. On the other hand, if someone thinks that their 2000 lb heim-jointed-non-bushing-having-engine-1-foot-away-500hp car is going to "have a real smooth ride", well, not sure what to say there. I sort of doubt it will.
I do think anti roll bars are very useful for allowing tuning at a track - as long as you have an adjustable anti-roll bar. If you do not have an adjustable bar then all you can do to tune it is unhook one side of the bar and disconnect the spring entirely. Malcolm and I had great success with this at Donnington a couple years back in the rain and it really transformed the car allowing us to correct a gross understeer issue in the rain. We've also run our SCCA Miatas in the rain with the bar disconnected to help it get some bite that it would otherwise not have due to the size of the roll bar on the car, it was quite stiff.
I think your development should be spent on springs, height, tires, and shocks to get the handling where you want it. Then you can add a small bar if you want to get some adjustability from it an tune for different drivers/tracks. As far as adding it to the RCR chassis I don't see that it will be hard at all. Two roll bar mounts/bushings can be bolted low on the front bulkhead on the outside under the clip. The bar will mount there, and then come around to the lower arms. A standard roll bar mount kit from Pegasus can be used to attach the bar to the lower control arm wherever you'd like to drill the holes for the mount. But as far as a roll bar being 100% necessary for a sharp handling car I'd disagree.
The slick trick would be to use a cockpit adjustable bar, although that is really icing on the cake. Design of this isn't as hard as you might think and is outlined in Carroll Smith's Chassis Tuning book. One of the end links is designed to slide up and down the arm thereby changing the leverage on the bar. A steel push/pull cable can move the end link for you and these mechanisms are available at race outfitters.
Oh, and I might fit one for tunability, but not to make it work. It'll be after I get it close.
Ron
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