The spermen box has a spear that is being carried in 2 hands, which you could use for a front rank. Then just add cloacks with green stuff.

I think that you are better off with the PG models, unless you are really good at conversions. They are pretty great miniatures albeit a bit expensive.

 

I guess spearmen as described above would be good,but it sounds like more trouble than it's worth.

 

all conversions are more trouble than they're worth. But if that's what you like to do and have the time to do it, there are several ways to do it. And you can do it cheaply or expensively depending on how good you want them too look. It sounds like you want a cheap derivative. In reality, most conversions are not cheaper. Look on ebay or on forums and usually you can buy High elf stuff for at least 50% off.

There is a company in Poland that makes elf bodies (legs and torsos) to which you could add halberd arms and elf heads, but once again, after collecting all the bits in the appropriate quantaties, you'd probably have been better off just buying some PG.

 

In the Noble and dragon plastic box sets there are some awesome looking halberds. On ebay yesterday i saw a guy just selling the weapons from those boxes for like 99cents there were about 5-6 items. So that could be an option and halberds look really cool. Although they may be very big.