boomtho: Many people know much more about schemes than I do (including our new DC, hopefully!) so I'll opine more generally. First, I'd like our DC to actually be a plus recruiter. Kaufman was basically a non-factor, and we've seen how that gap in our coaches' recruiting ability translated into a lack of depth and top-end defensive talent. We need a DC to come in and re-engage on that aspect to really drive momentum, especially short term.
Second, I'd like our DC to have experience in a conference that faces a wide variety of offensive schemes. As an example, I'd probably prefer someone from the Big 10 (where you see spread like tOSU as well as power-I football with Michigan) over someone from the Big 12 (where it's a lot more spread/run-and-shoot oriented).
Schematically, I'm not one of the people aboard the "all pressure, all the time" bandwagons. I'm pretty OK with any scheme as long as the DC is willing to adjust to accommodate existing talent and groups of positional strength (e.g., if he wanted to go 4-4 with our LB's... that would be concerning).
Piotr Le: Nerding out on the scheme here. I am actually a fan of an hyper aggressive 4-3 or 3-4 with man press corners. Due to our personnel and lack of good, space eating DTs we won’t be able to run my all-time favorite Wide-9 scheme (a la Jim Schwartz with the Eagles or Mike Zimmer with the Vikings). What we can do is run a 4-2-5 with two ILBs and rush the passer as often as we can with blitzes of the edges either with a NB or SS blitz while keeping our DBs man-on-man with Cover 1 or 2 shells from the Safeties.
I don’t have any DC’s in mind, but I think Cal can get a good position coach of a solid defense who wants to prove himself. The level of talent in the front 7 would be of utmost concern for the coach. However, we can sell them on a veteran secondary that had a lot of the players play this year due to injuries. Plus we have at least 1 All-Pac 12 (in my opinion) corner in Darius Allensworth and a very promising safety in Evan Rambo.