I believe you are using the be verb incorrectly. We don't normally use it this way.
I would appreciate any suggestions.
I would appreciate it if you could give me some suggestions.
Maybe someone could say "I would be very appreciative of any suggestions" but it seems strange. Do not use the be verb. Also the difference between can and could is not a big one, to me both would be fine but I believe the modal could would be more appropriate.
hope this helps,
Nick