pussnboots - I asked my vet the same question with my last old cat. He said that in theory it is a good idea, but it depends on the character of your present cats. Mine was old and grumpy and I didn't think it would work.
When he died I adopted 2 18 month old morons.
bigmamma - cats look adorable. My tom is currently behind my desk pulling on the mouse wire and trying to balance on a TFT screen. His sister is too lazy to try anything like that - but she has a mean streak and regularly injures her brother. He has been to the vet twice in the last six months with infected wounds. He never hits her back, not sure if he is a wimp or brought up not to hit girls!
They are sweet and lovely cats - but they drive me nuts.
Good luck pussnboots.
SusannFrankienPrincessMerlin