120 archery
120 tactics
120 bushido
100 necromancy
100 resist
80 chivalry
80 in either spirit speak (wraith form/familiars/spell damage/curse weapon for more leeching), anatomy (more damage = more leeching) or meditation (mana regen)
You'll need to use chivalry for curing, bushido's concentrate for emergency heals and vampire form. Maybe animate dead on occasion. If you don't have SSI, stamina and mana leech on your bow, you can pretty much forget about it in PvM.
Or maybe this one:
120 archery
120 tactics
120 anatomy
100 healing
100 resist
100 necromancy
60 chivalry
You don't get lightning strikes or confidence, but you do get healing and do more damage.
Or maybe... well, there are many templates you can use.
120 archery is vital
Some chivalry is vital (enough for consecrate weapon. Mischief maker is a silly bow, but great if you have consecrate weapon)
And I suppose if you insist on necromancy (totally not mandatory on an archer who wants high level content), 100 points there.
The rest of the skills are build-to-choice skills and depends on how you want to play it.