Welcome to the mad house.
On the assumption that money isn't a controlling factor, I'd go for the R.
Most owners end up wanting more power, better this, better that. The higher up the chain in standard spec you start the better.
If your used to a reasonable bike then the R will be much closer to your expectations, I assume that you've driven these cars from a Caterham showroom and as you said only for some few minutes each, in which case I doubt you were really "pushing on" when you own a car and have got used to it you will use the top end of the rev band much more, this is where the difference between the two is to be found.
The SV option is good for touring, simple because you can get more in.