Here's a general outline that will get you started thinking about your build... a lot is going to depend upon your playstyle, and what you want the character to do (and the level you want to reach. I'm assuming 30?).
I'm guessing that the 1H backup means you want to be frontline tank.
In this case, a build with minimal conversions sounds best so that you can have high IF and Shield to hold the line:
21/15 - Having only 5 WM to split between 2 weapon types strikes me as pretty blah (you can just barely get both over 100 WPF). Plus only 5 ATH... ugh.
15/21 - 5 PS sounds really frustrating when you don't have a boatload of AGI to make up the difference with speed bonus.
18/18 - Balanced. Your ATH/PS won't be 7s, but they also won't be 5s. Enough WPF to split moderately well (123/125 or 139/101 depending on which you favor), and enough HP (65) to keep you alive on the front line. Worst case, it's a 'neutral base' that you can adjust the following gen if you decide you want to hit a little bit harder or be a half step quicker.
As for backup weapons, again it's going to come down to playstyle (and your WPF distribution). Are you:
-Spear-Heavy: You are a hoplite who primarily uses the spear and only switches to the 1H backup as a last resort.
-Balanced: You are a hoplite who switches back and forth between weapons as the situation dictates.
-Sword-Heavy:You are effectively a 1H shielder who happens to carry a spear to get a few pokes in before switching to 1H
In any case, you'll want your backup weapon to be on the short-side (your spear is here for reach-fights, your backup is for facehug fights).
You may even want to have a couple of weapons in your inventory so you can spawn with the right 'tool' depending on the enemy team's makeup.
Lots of shielders? Bring an axe.
Lots of plate? Bring a steel pick.
General mix? Bring a short sword.
(A mace class weapon strikes me as a bit too heavy for a backup).
As always, the only thing that really matters is whether or not the build is fun to play and feels rewarding. This should help get you started.
Cheers!