Random Fanticide questions.

[Ray Earle]

Hi guys,

I'm looking at these rules for fantasy but thinking of using old classic Warhammer figures that I've had for the last 25 odd years (got to paint them some time  ) along with some I've obtained from trades on LAF. Thanks guys!! 

I've had a bit of a browse through t'net but haven't come up with the answers, so I wanted to know if there are any specific basing conventions? Particular sizes for different figures, or is it fairly freestyle on base diameter? Also, roughly how many figures to each unit?

Ta,