There are several Shaiya priest builds for you.For all classes,built is important, but this class allows you to make an unique toon with unique qualities and shortcomings.Ok,read it up now.

Full builts

Best party oracle/priest. Either WIS or INT (healer, or nuker), you'd do your job good (in PvE). In order to level the toon fast, you'd better go full WIS to boost your heals, as healers are always well accepted in party, that can generate good exp(If you think leveling is low, you can buy Shaiya(buy shaiya items) powerleveling to upgrade your character).

Full REC built is something that I've never tried (ok, only several levels, I admit...), but I guess you'll meet the prejudice of the people, framed in the concept that priest/oracle should only heal and never try to be different, even more than as an INT oracle/priest.

Mixed builts

You have the healing abilities, so you can use them and upgrade them with either some attacking power (adding INT) or some deffence (adding REC). As the second works good even for PvP, my own experience shows that first works awesome in PvE, but not as good as needed for PvP. But after all, its fun to play, if you like PvE and want to stick with it. (My case was such, when I realized, that healers actually are too week for PvP if they do their built as its "meant to be done" - higher the heals, lower the defence.)

As NM offers less stat points, in order to make a good toon that is easy to get party, most people will use the full builts to boost one of their options (healer, attacker, or surviver), usually their ability to be healers (no other class can heal, and, lets admit it, people still prefer the oracle/priest stay back and heal).

HM offers you some more stat points, so you can play with the built and boost one of your extra ability, or even make it a main ability. It all depends on your own style.

UM can give you so much stat points, that you can easy play with your built, in order to make it the best built to suit your playing style. You can ever take it to the next level:

Balanced builts

You can keep your healing ability (WIS), make yourself survive good and help with the dmg. But remember, you can never be good in everything. Who knows, this builts could be awesome if you are able to make your gear awesome. But you never know if the opponent has gear and built more awesome than yours.