Longbow if you are used to placing shots with care and want to shoot targets that you are fully aware of.
Rus Bow for not-so-extreme more balanced Longbow. Good for anti-horse operations and taking out heavy targets.
Horn Bow for best bow overall (the most balanced, there is no "best bow" everything has a purpose), very good for horseback or as a ground archer. If this is your first gen, us this bow.
Any other bow is for very specialist purposes or thematic use.
I suggest a 21/18 build at level 30. This gives 7PD, 6Wm, 6ATHL, and enough left over points to put into IF or PS, your call. Alternatively if you feel you have a steady hand, going 18/21 might be better. Try a STF character with an Alt just to test things out first.