Yeah powerbands...... the thing that I was thinking was this.....
I find driving a car on tarmac is easier to keep in the powermaking rev range, compared with "TIGHT" dirt tracks.. ie Hairpin turns in gravel. I attribute this to having to slow down sufficiently to attack the corner at good angles, and not wanting to FORCE (read: crunch 1st) it back into 1st to get good acceleration out of the turn. Don't forget it could just be my amount of experience on dirt and gravel!!
As for building an engine if your getting into rally, my suggestion would be to not worry about making the most revs.... grab a 20V and go from there..... 9000 RPM from a 20 V is attainable and a bit more forgiving on the wallet!
Don't forget about the 16V's also..... most people tend to forget about them because they produce less power from the factory but they are a great engine that still offer heaps of potential. But as with most things in life.... it all costs money!!
PS: Where about are you from and what catagory are you planning to campainge this car??