Very good advice from Diomedes there.
Another thing.
Shielders usually need less armor, because their shield can defend so well, and suck up more hits than any black armor no-shielder.
This makes you faster, both in terms of wpf weigh penalty, and moving faster.. I don't understand why shielders would wear any heavy armor actually, unless very high level. You are more dangerous with light armor, and it is a great exercise in awareness from ranged + horses etc.
Highly theoretical from my side of course, as I rarely tried a 1h char but: :-)
But to me the best shielder build would be a somehow light armor, only 6 PS and rest Agi, high shield skill and athletics. Carry a scimi for cloth, a pick/hammer for armor, and a pike/spear of some sort. (no polearm wpf though)