In general, you should play the offense the team knows ... it takes at least a full season to change offenses and get IQs high enough to make the change work out (unless you are starting all underclassmen ... which is a good time to change offense or defense if that is what you want to do).
If you are going to change, flex sounds like the one you want (if you are keeping those attributes going forward). From hoops101:
Doesn't require a big presence inside to be effective, allows the offense to spread the floor and use quickness to penetrate to the basket or draw the defense in for open outside shots. Requires good passing, speed and outside shooting.