Making a community in flash?

Hi!
I am thinking about making a community in flash.
I have made a community in php/html before, so I have enough with skills in php/mysql/html etc.

Just wondering if it will be hard of making a community combining flash & php?

I will add following to the community:

*onlinelist
*guestbook
*member searchfunction
*mail
*diary
*chat
*profile
*etc etc…

I really want to hear your suggestions… thanx, SanTiago_99