There is nothing wrong with having a football match between BHA supporters and Palace supporters but I think an all singing all dancing affair is perhaps too much to expect.
You need commitment of people in organising it (difficult, particularly when it raises very little money), commitment...
Have you considered Southwick? After all it is the venue where the first REMF match was played.
I know it is not as glamorous - but it has a bar! And you may find you get a bit more interest from local people away from Withdean.
Last year we had good publicity but virtually no-one turned up...