Do you really need different spikes though? A quick look at the owners manual indicates the spikes supplied with the speakers are good for both wood and carpeted floors. Here's an excerpt:
FLOOR REQUIREMENTS
The floor in the location selected
for setting up the Project K2 S5800
speakers must be capable of supporting
a load of 185 lb (84kg).
Because of the coupling effect of
the stainless steel feet, a flat, hard
surface such as wood or linoleum
is preferable. However, the design
of the loudspeaker’s coupling system,
along with the speaker’s
extreme weight, should result in
excellent performance on any
surface, even on carpets.
To prevent indentations on wood
or linoleum floors caused by the
weight of the loudspeaker, always
utilize the enclosed coasters. Do
not set up the Project K2 S5800
system directly on a ceramic tile
floor; the concentrated weight
might cause the tiles to crack.