Signatures Limitations

Is there a setting where i can limit the size of ones signature to a number of lines or so. Some members business banners absolutely huge and would like to make it so its denied if exceed signature limit.

Nope, 1,000 is the maximum sig size, however, you can choose groups which can only have their sigs displayed on their posts:
Admin Panel > Users & groups > User Options > User Settings > Allow Signatures : Groups > transfer the groups that you want to allow to have their sigs to the 'Allowed' column > save

It's a real pity you can't limit the size of signatures