depend how long you want use it and what lvl you reach on buffer
if want 78+ make EE (powa/clarity/wm), you can buy acu pots in shop/priest and can buy event scrolls with emp
if need max about 74 make SE (emp/WM), acu potions from shop/priest
if need only to 40-50 make PP
if can box 3 clients make EE+SE - best way