Draft First, then the Fireworks
IMHO, who you acquire as a FA big depends largely on who you end up drafting.
1) Do you trade up in the draft? If so, to acquire Enes Kanter or a top PG?
2) Do you stay at #17? If so, do you draft Faried or Noguiera or a midling PG?
3) Do you keep #17 and trade for an additional first rounder? If so, do you draft Faried and Noguiera, or just one of these and a guard?
If you have some project bigs (Jerome Jordan, Noguiera, Faried) then you might acquire Dalembert or Foster, so you can also get a better PG backup, pending a CP3 deal or keeping Billups for more than another year.
If you draft a PG of the future, or just Faried but not Kanter or Noguiera; then you might need to go for a better longer-term center, such as Marc Gasol or DeAndre Jordan.