WOW that was a very nice system! Well I think you could build a good system for vastly less though the GPU will be the kicker this time around. I haven played with the quadro series much but a new sandy bridge system could do wonders for your processing times. I am sure you could do fine with a 1155 but personally I think a 2011 or sandy bridge-e would be perfect for this set-up. I have a feeling you eat through some RAM and a newer GPU would be good too! You could carry some items over if you wanted but i think with prices on most things where they are a new build would net you some good results.
Are there any peripheral connections that you require? What kind of case are you looking for, i.e. full tower, business look, no LED fans, etc.?
Here is a preliminary build:http://secure.newegg.com/WishList/PublicWishDetail.aspx?WishListNumber=19168286