Yes that will work for a single DSL.
If you get a second dsl wic you should be able to multilink the two
together. We do it with T-1's for customers already. Of course you will need
the right IOS to do ppp multilink.






Would something like this:

 
http://cgi.ebay.com/Cisco-1721-w-WIC-1ADSL-DSL-Router-1700_W0QQitemZ23029263
5882QQcmdZViewItemQQptZCOMP_EN_Routers?hash=item230292635882&_trksid=p3286.c
0.m14&_trkparms=72%3A1205|66%3A2|65%3A12|39%3A1|240%3A1318|301%3A1|293%3A1|2
94%3A50

work?  It is a "Cisco 1721 w/ WIC-1ADSL *DSL Router* 1700".

Thanks,
florin