Help needed in transition to HD !

We produce 45 episodes of a show that needs to be delivered on 1080i 59.94 HDCAM. We are currently an SD tape operation but need to move up. Because of the amount of video we gather, archive and use on a regular basis, I would like to acquire and edit at a lower frame size and convert up via the aja as we lay back to tape. I have a chart that shows me about every HD format and how many TB's will store how many hours, but it doesn't include XDCAM from the EX. I know it records in a variety of frame sizes and rates, but does anyone have a chart that shows me storage scenarios ? The other question I posted on the DVCpro area was... has anyone shot at a smaller than 1080 frame size and up converted to HDcam 1080i 59.94, if so, how did your image look. (assume there is a decent DP etc etc) What I am hoping to do is shoot a native image that holds up during the conversion but gets me a lot of hours on whatever storage device we choose. Thanks for the help

Dave