transforming Dolphin into house exchange

Hi,
first we're not yet sure if we actually will go with Dolphin. This offer is not definitive since we need some price estimates first to see if it is doable for us.

We want Dolphin to be redefined as a house exchange service.

- Matching fields (looking for) must be transformed to location, number of rooms, bedrooms, etc.
- fixed fields related to a dating service like Zodiac must be removed
- Payment must be altered to support a time based membership (1 year)
- Template X-Gravity must be modified to reflect the changes stated above (profile page, search options)
- the system should be a closed system, so you can only access the site with a valid membership
- members can only join with an email invitation sent by someone who is already a member


This is roughly what we want to be changed and what we need a ballpark estimate for. If you see details that we didn't include, and feel that they would be necessary for our goal please take them into account, and mention them in your bid, so that we know what is included in your bid.