Which assembler?

["Kallikak" <ken.wessen@gmail.com>]

Hi,

I'm after a 6502 assembler for my Apples, and am hoping for some advice
on the best one to choose.  Although I realise it may not be possible
for all my requirements to be met, here is what would be ideal:
  1.  Comes on a single disk,
  2.  At least basic documentation is downloadable somewhere,
  3.  Can run on a 64K Apple II+ (though I have a 128K IIe and a IIc as
well)
  4.  Uses a relatively standard syntax - e.g. hopefully things like
LDA ($300),Y rather than LDAIY $300 etc
  5.  I'm sure they'll all support symbols, macros aren't so important
to me, but an include facility would be nice.

Thanks in advance for any suggestions.

Ken