Filemaker consultancy needed

We're a small business, based in France, looking for some help with further developing a Filemaker database which has until now been created in house.

What do we do?
We have a private house with staff, available to rent for parties, weddings and holidays. The usual thing is that one client takes a booking for all of the bedrooms in entire house, which is pretty straight forwards. Perhaps two or three times a year we set up a special event when we sell the rooms individually, each room to a different client, much as a normal hotel would do.

What have we got so far?
My husband has spent the past year creating a database using Filemaker, specifically to manage the wedding planning process within our business. This existing database records client details, supplier details and various aspects of the wedding weekend and generates reports using this information for our brides, caterers, housekeeping team, etc. The programme is accessed by three wedding planners and is working nicely.

This is not the first business database we have developed and we have always erred away from bringing in outside help since we don't want to be stuck with something that no one understands or can fix etc but we have now reached a stage where my husband is too busy with other things to spend sufficient time to take the database where we want it to go. We are therefore looking for external help to take the database to the next level but to do so in a fashion which is sympathetic to the initial design and to provide sufficient explanation to my husband that he will be able to continue with it's management and upkeep.

What do we want?
We want to further build on the existing database to include all bookings, rather than just the wedding bookings. We particularly want to include a calendar facility, and the option of switching between whole house bookings and instances when the house is booked on a per room basis for the same dates rather like a hotel. So we need to switch between Whole House and Hotel Bookings.

1. The calendar feature
We need to see a month or several months on the screen at one time with dates identified as booked, optioned or available. Where dates are booked or optioned the relevant clients should be displayed with a facility to click through to their booking details. One small aspect to be aware of here is that we usually turnaround the hotel on the same day so there's often a confusion in the mind of the database since client A has booked 1st to 3rd of March in which case client B cannot start a booking on 3rd March since client A is still there. We need an AM/PM check out, check in option. We need a feature which prevents me from double booking the same dates.

2. The Whole House / Hotel division
The database has been set up on the premise of one client taking the entire house but several times a year we run a weekend course or similar when individual clients book individual rooms. These clients might already be in the database, existing clients so we would not want to start a whole separate database for them but it does feel like a separate section of the main database and we need to account for individual arrival and departure dates. We also need to build in a feature which allocates each of these clients to a specific room and prevents double booking of a room.

Timeframe
This is not a job which must be completed this week but we do need to have something in place before the end October in order that we can settle things before the wedding planning season starts again

Questions

Do you have any previous experience of calendars and filemaker or of hotel style databases?
Can you provide any references for previous contracts?
How soon are you available to start?
How many projets would you be working on at one time
How long do you envisage this would take you?