Yes thanks, I did hear about the possibility with Bootcamp to use Vista on a second hard drive, of course an other great reason for the Mac Pro! 

Thanks Greg for your additional info. Yea, that's the thing with the Mac Pro that makes it so quickly costly, I do need to get a monitor. Not thinking that I could buy RAMs and all elsewhere I had calculated double the price of the iMac which is a lot since I'm not quite pro yet and my renders are not that demanding. 

This is all so helpful to better see my options, a lot to think about! Tough choice trying to wisely evaluate my needs for now...

Really appreciate all your pointers, 
Gwenolye