I used Rey and Daka in my arena team until the mid-60s and could get into the top 20 with them. But I had to replace them. With Level 60 the fleet store open and many people get a Wedge to their Biggs which can just oneshot Rey. With gearlevel 8 protection is so high that healers are less effective. So don't put too much energy on Rey, Lumi and Daka, although they might serve you well in GW and Rey can improve your raid rankings.
Barriss is not that great in arena (its different in endgame with zeta), but also very good for GW.
Wedge and Biggs are classic and very good in the midgame, you can start farming Wegde in the fleet store. Boba is also great. You should get a tank, either STHan (Arena) or Sun Fac (Fleet). Use your GW tokens on Biggs and ships.
The 60s are a good time to rethink your arena team. Gearing is easy because alot of purple gear will come from new challenge rewards. I changed my complete arena team between rank 60 and 70 without loosing ranks.
