Derald,
First I would have to disagree with those promoting Miva for your client. Yes, Miva is a great app. The issue is with the overall needs of the client. Miva is a stand-alone application that will not easily integrate into a backend user interface that would handle all your clients needs. You want to create something so that all of these requirements can be accessed through one interface. Miva will not allow that, and the database integration would need to be separate from the rest of the databases.
If you do not have the connections for the backend development, I would suggest going to
http://www.elance.com. You can post for free and you would be surprised how quickly your quotes come in. Many developers have already done just what you are looking for and only have to adjust a few minor things to accommodate your needs. Makes for quick turn around. I would make sure you know exactly what the server type is, databasing structure, and programming language that is to be used. And give a low bid rate. You will usually come in under and have some buffer from their offer to play with. If you have buffer and the programmer pulls through early, I usually kick them a little extra. They appreciate it, and cut me deals in the future for programming.
Also, make sure that you have specifics down in the contract. This way the client can't put things in under the wire. Keep them honest.
I hope this helps. Best of luck.