Well the pattern to date has been to run Joseph as a 2 or 3 tech and Canty (or Bernard/Kuhn) as a 1 or 2 tech.
If we're replacing Canty with this draft, presumably we'd go that route. However I'd say the only DT we'd definitely stay away from is a pure 0 tech (your 3-4 NT).
The differences between a 1, 2 and 3 tech DT are more about defensive alignment than player specialization (some notable historical exceptions aside).
I would guess that most NFL teams will see the following as pure 0 tech prospects:
1) Star Lotulelei (although he can probably play any DT position due to his athleticism)
2) Jesse Williams (has moved from DE to 0 tech ... doubt he goes back)
3) Jonathan Hankins (doesn't have the motor for a 3-tech)
4) John Jenkins (the DC who doesn't play this guy as a NT should be fired)
Sheldon Richardson and Shariff Floyd would be my top prospects in that list (assuming Star is off the board of course).
There's a better than even shot that both of those guys are off the boards with our first pick, so I'm thinking CB in the first and someone like Kwann Short in the second or Sylvester Williams in the 3rd.