Designing a Customer Relations Manager

I'm trying to decide what would be the best approach to design a Customer Relations Manager. There's already a complete "Contacts Manager" in place (FM7), which is (or will be) used as a starting point for the CRM, debet control and some other databases (in a small fashion company).

I'm a novice developer, and often struggling to wrap my head around relationships (of the database kind). Some things I can get to work, some not...

The CRM is fairly simple: it is used to track conversations between the sales dept. and customers. A short topic line, and longer input field where the gist of the conversation is filled in. Was it by tel, fax, email ? Is it a new topic, open, or closed ? Dates, persons, etc...

What I would like to develop, is something akin to a forum (like this one), where each customer (about 250) has - or will have - his own list of topics, which can be "opened", "followed-up", or "closed". Each rep of the sales dept. should be able to go into the CRM database, select a customer, and "post" a new topic, or follow up, etc...

As I see it now, I should have a database with 250 records (the current customers), with auto-adding of new records when a new customer is created in the (external) Contact Manager database. Each of these records has the ability to list all of the topics, and of course create new topics. Note: creation of new Customer records should be prohibited from within the CRM database.

What would be the best approach to something like this, or are there better ways of doing this ? Any ideas, hopefully none too complex ?

Thanks.