Also, you mention that you have already ripped your DVD's to your server. How did you do that? (Hardware?)
You can rip any DVD providing you have the right software to do it. I personally use DVD Decryptor on older titles. On newer ones I use RipIt4Me and DVD Decryptor, to get around the protection. There is also DVDFab and AnyDVD are other popular programs to use.
Do you think it pays to buy a blue ray burner as part of the system?
Spend your money how you want. Again, personally, the new high def DVD's are not worth it yet. First, it is like a VHS/Betamax war...who is going to come out on top? Second, aren't burners pretty expensive? Third, you will have problems trying to rip a Blue Ray disk with all the DRM protection and crap right now. The technology is to new and there aren't many hacks out yet to allow you to rip a blue ray disk. Again, my own personal view, wait for the price of a dual burner to come down to something reasonable, then you will have the joy of burning blue ray or HDDVD, and who cares which format then comes out on top.
Each to their own though.