Going to get a Mac Pro-Questions

The situation I have is both me and my wife have a home based business. Each of us has a MBP that we use for both personal and business use. We store a lot of personal files such as office documents, itunes music, and iphoto pictures. Also, for business we have many office documents and other important files. I have wanted to get a desktop Mac which I can use for a backup if one of the MBP's goes down while it's under repair or when we need an extra computer or even computing power. I like the design of the iMac but coming from the PC world I always built my own towers and like the idea that I can do a lot of expansion to the mac pro. I just have several questions:

1. The way I am setting it up I want to have it set up for dual use. I plan to put it at my desk but then get a wireless/bluetooth keyboard/mouse. That way I can use it at my desk when needed and when my wife needs it she can. Her desk is just 12 feet away and I think the wireless should work fine at the distance. We plan to get a widescreen monitor for both desks but my question is, how far will a monitor (DVI) cable work. It would be at least 20-25 feet since I'd have to run it along the ceiling and across a door. Also, if I am able to do this what is a good Switchbox I should look at for the monitor?

2. I have a question about the drives. I understand the current Mac Pro works with up to 4 hard drives. I want to dedicate the 1st one as purely for this machine for Mac and Windows, likely 750GB or more. What I want to do beyond that though is set up a server drive to be used from both of the MBP's. if I'm right the Mac Pro can do RAID and would want to have these as mirrored drive. Could I simply get a couple 1TB drives and make it drive 2 and 3 and set them up to do Mirrored RAID? Can I do this with the standard MAC OS X or do I need to get the server edition? Also, does the standard Mac Pro support it or do I need to get a RAID card? Beyond this I want to start using Time Machine from both MBP's. I know I can set up a 4th drive and make it dual partition but I want to use two separate drives so I don't risk losing both time machine backups if a hard drive fails. Also, I want at least 750GB for the Time Machine drive so I plan to get a couple External HD's to simply operate via firewire or USB that can be attached to the Mac Pro.

3. I originally was going to set it up as a Boot Camp machine. The machine this is replacing is a Tower Windows machine. I have tried both Parallels and VMWare in the past but have never settled on either. I am not much of a gamer, I only play Flight Simulator from time to time and other than that other than programs like Quickbooks I don't use Windows a lot. I still want to have that option but with the power of the Mac Pro will I be able to simply use Parallels or VMWare instead of using Boot Camp? Which one is a better option?

4. Power: How much wattage would a computer like this use?

5. The Next Mac Pro: I know many things like memory, hard drive sizes, design, graphics card, etc. may all be unknown for the next mac Pro but what chip is expected to be used in it? Is there a newer Xeon or some other Intel Dual or Quad Core chip?

I know these are a lot of questions and of course we are facing a update. I definitely will wait for the updated Mac Pro but want to make the right purchase decision. I appreciate any help with this.