There is nothing wrong with fFash as long as you don't have long download times.
The major problem with any site is… click wait, wait, wait, wait, wait, wait, wait… image. Click wait, wait, wait, wait, wait, wait, wait… image. Click wait, wait, wait, wait, wait, wait, wait… image. Click wait, wait, wait, wait, wait, wait, wait… image.
The first point of call I would suggest is that you visit similar sites to what you want and see what works and what doesn't. That is, put yourself in the customers chair and see through their eyes what is important.
Having visited a number of photography sites recently my top three musts are:
1 Good navigation
2 A minimal number of clicks
3 Good download times.
Flash is not the problem. Good design is and you should be willing to pay for it, just like you expect clients to pay for your skills.
Cheers,