Now did I open a can of worms

I need to walk over 400 sites and I expect a variety of retrieval speeds.
I've tried specifying the 400 sites using two -m options (one for the -j's
and one for the list of urls to be walked) but this doesn't seem to work.
Looks like the URL of the site to be visited must be on the command line.
How am I to index the list? Do I need to run sequential GW's now?