u should think about a combination, since (community correct me if i am wrong) 5 pdraw with strongbow is not a good option - same for 4 and kergit.
i retired an archer yesterday with 170 archery, 5 pdraw and a fine strongbow - quite accurate with strongbow if u release the arrows instantly, but then i picked up a fine kergit for fun and noticed that it was much much more accurate and safe for my teammates... with the strongbow it's a bit luck where ur arrows go when u hold it for more than about 0,5 seconds with 5 pdraw.
atm i have 6 pdraw with masterwork strongbow and 140 wpf - still i cant hold it long enough. but i dont know if the solution is pd up to 7 or more wpf..
so, think about the kergit with a 15/24 build.
pdraw gives u damage and as far as i know still a passive increase to arrow traveling speed.
i dont really know what pdraw does to accuracy, but i think that with every pdraw over requirement u can hold the bow longer without having the reticule over whole screen.