If your two LNBFs are dual output standard (L.O. 10750) models, I'd use a 4 x 4 22k switch to switch between the LNBFs. This would give you four outputs for your digital receivers that would all be capable of seeing both polarities from both LNBFs.
I'd slave the analog receiver to one of the digital receivers. You'll probably need an AV multiswitch (or modern A/V audio/video amp) to route all of those video outputs (including your VCR) to your TV or monitor.
If you want to keep the single output LNBFs, you'll have to use a splitter and only one receiver will be able to control polarity. Make sure the splitter will handle up to 2 ghz, and that DC is blocked on all but one leg (the leg you will put the polarity-controlling receiver on).