"Any suggestions as to which gun is the better preformer?"
Obviously, the R-1 shoots harder with every caliber. That increased performance does come at a price. The price is the R-1 is generally about $150.00 for expensive, at LEAST a pound heavier, and generally requires a heavier-duty scope.
If I were to do MOSTLY hunting, an .22 R-1 is the obvious choice. A .22 caliber hole always seems to kill quicker than the .177 or .20.
If I were to do mostly TARGET shooting or plinking, an R-9 .177 is the obvious choice. An R-9 .177 will shoot MOST pellets well, even those at Wal-Mart. .177 caliber pellets are ALWAYS cheaper too. A .177 gun will shoot flatter than a .20 or .22 from the same gun. And to be perfectly honest, I have killed the most squirrels with a .177! Head/shoulder shots always work!
Saying all this, I have a R-9 .20 and a R-1 .20 Carbine that I will never part with. Two of my very favoite air rifles, I have killed a pile of squirrels with each. .20 caliber guns ARE more finicky about what they shoot well. The better .20 caliber pellets probably will have to be ordered, so you have to plan ahead.