I would definitely say dont spend any more big bucks on FA's until the arena gets going. of all the advice given, thats probably the biggest issue i see with what you've done so far, should not be spending almost your entire bank roll on big players, you can compete in D.V with relatively minimal salary (i had nobody over 10k salary, just a handful of 7-9k salaries.
if your guards are it, i'd say Motion if they have average range, and RnG if they have good range.