The heads are an improvement on the WF ones (which, for those that haven't seen them, have mould lines right where you wouldn't want them), but maybe a little big for the WF torsos.
You could try the Brigade zombies - either the WW2 germans (I paint them up as moderns), or the new modern civilians, for a bit of variety - the former come with two head options, so you'd have some spares to use on the WF ones.
As bad as the WF heads are, for me, the mismatch between the torsos and legs is as much a problem - without a lot of additional work, they just look odd as single models. I plan to "hide" the WF ones i've bought, in the centre of hordes, where the waistlines aren't visible.
Costwise, as i mentioned on the thread on GWP (which i'm assuming is yours as well?), both the Brigade modern civvies, and the Mississinewa minis are pretty competitive costwise - i've just taken up Brigades 50 zeds for $80 offer, and the last batch of c20 zeds I bought from mississinewa cost me about $25 inclu P&P to the UK.
{cue Scurv, accusing me of being a WF hater...again...} 