Pen testing a very small network

["Sekurity Wizard" <s.wizard () boundariez com>]

Hey y'all,
        I'm doing a pen test for a very small client, and I've found
basically that they're behind a very ghetto IDS which will forever
auto-block you if you port-scan them, haha, that aside, I find all
Microsoft Server 2003 based stuff.  Here's a litany of what I've found,
perhaps you can make some recommendations?

- IIS/6.0 as the web server
- MS VPN -pptp (tcp/1723) open
- Ipswitch WS_FTPd 5.0.4 running with the "ssl vpn" option *only*
- IMAP open
- MS Exchange OWA running at http://xxx.xxx.xxx/exchange (using basic
auth!)

I guess I have some specifics - as far as questions go.  I've got a
linux box I can ssh to and pen test from (since they've blocked my
regular Source IPs).  Is there a linux-cmd line script that'll cycle
through and attempt to brute-force a password for a username I already
know?
What about the Ipswitch WS_FTPd running?  I know 5.0.3 is vulnerable to
a bunch of stuff, but does anyone have any recommendations for 5.0.4?

Anyway - thanks.

Cheers.

\\`izard