asterisk users - May 2005 - Connecting a couple DS0's to a wildcard

There's a project to use asterisk to replace an old analog pbx for a
hospital in Mexico.
The person in charge wants to do a trial before making a large
investment. For this test, he is willing to buy a Wildcard TE410P.
Hes got a proposal from his pstn provider to convert his analog lines
to digital ones, but I have some doubts. Let's say he converts only 2
or three of the lines.
He would get two or three DS0's, wouldn't he?
Now, if that were the case, would it be possible to connect these to
the TE410P? Is it just that only three time slots are used and the
others are blank, or signalling is different between the cases you
don't have a  full E1?

Thanks in advance
Jaime Atahualpa Lopez Sollano