Hello there well for Balance/Madness on my sage and sorc i use the same build as pve first.
Second for Gear here is my current gear:
Sage 7 pieces with Power Surge, 1 Crit Surge and one Power Alacrity. Thats with gear including ear piece, 1 implant, maind hand and offhand.
2nd implant I went with accuracy power (been testing it out and comparing it with power surge)
Relics: Main Stat and Power
Sorc:
Sorc: Full power Surge on everything.
Both sage and sorc are mods and enhancement mix maxed.
I've notice some difference with full power surge on my sorc, if i were to compare my sage and sorc i would say i am satisfied with my sage the way the gear is since im able to provide a lot of deeps on wz's .
The difference in gear between my two toons is minimal tbh but my sage seems better in pvp than my sorc.
Then again its up to you to play with gear and try it so you feel comfortable about it.
I can link my ARM profile if you want and build just let me know .
Hope this helps.