Write some Software

My client needs an accounting system. It is a small business. Unfortunately they tried Quickbooks and Peachtree and they both don't have some of the functionality they need. They need ability to customize it a little bit. They need to have few extra fields to track some additonal information. What we are looking for is either a small accounting package solution that is good for small business but supports some basic customization and gives us abilitiy to add some extra fields on the forms. Or you can propose to create a custom application but we think that will end up being a big task. We are open.