[Limdep Nlogit List] Experimental Design Software for Conjoint

[infocorp]

Dear Limdep Users,

Is anyone able to recommend affordable experimental design generation
software which directly generates conjoint designs when attributes have
varying numbers of levels.

An hypothetical example of a conjoint task is:

1 x 2 level attribute
1 x 3 level attribute
1 x 4 level attribute
1 x 5 level attribute
1 x 6 level attribute
1 x 7 level attribute

SAS QC suggests generating designs with PROC FACTEX using powers of
prime numbers and then collapsing levels.

The 2 level attribute would be generated directly; the 3 level attribute
would be generated by interacting two 2 level attributes to give 4
levels, 2 of which would be collapsed; and so on until the 7 level
attribute would be generated by interacting three 2 level attributes to
give 8 levels, 2 of which would be collapsed.

Is there software available which will produce a design directly from
the specification above?

Ron