4 ftr pre epic for 1 extra attack per round (if the base class is a rogue, bard, assassin etc.) doesn't matter when you take them unless you need discipline in which case spread them out a bit for regular increases.
It's rogue (or another class with tumble) that is best taken on certain levels. 2, 7, 12, 17, etc... for the +1 AC.
F10/w1/AA29 is one of the best archers as is R13/w1/AA26. The second one would get you an XP penalty as a dwarf tho. F6/SD1/R23 is another wonderful archer with no XP penalty as dwarf. i think they will all be on the ECB, but I can post a build if you want.
Have fun
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