[cisco-voip] Cheap Platform for High Density FXS?

[chris]

I am looking for any advice on a cheap platform to connect high
amounts of FXS. The solution thats worked for me thus far has been
2600xm with nm-hda and the em-8fxs expansion gets me up to 12 fxs. It
seems to handle well and 2600xm is cheap in the graymarket plus small
form factor is nice for mounting in termination areas. I also like
that the NM-HDA uses the amphenol connector so its easy to connect to
a 66 block and let the wiring tech just punch down there.

I am just wondering if there is any way to get any more FXS out of
that platform? The part that sort of confuses me is that the IAD comes
in a 16 and 24fxs model and it seems like the IAD is basically a fixed
configuration of the 2600. I read in the datasheet for the NM-HDA that
you cant install more than one 8 port expansion module into the NM-hda
which is a shame it would have been nice to get 20 fxs that way

I would be open to other platforms if the price is fairly similar, I
looked at 2811 since it has more slots but the base platform is a bit
more costly and the associated NM and VIC2 cards are higher in price
as well

thanks
chris