Pay App Billing

I am fishing here for someone to get in contact with that also has Sage 100 and handles pay application's with general contactors? We have now steered more towards pay app type customers who require us to bill through their pay application software. It has become a headache for our team to match Sage to their pay app software in order to invoice them for the correct amounts. Also, these pay apps needs submitted by a certain time of the month and withhold retainage as well. Do we even license the correct Sage to handle this?