[AccessD] OT: WAN/VPN network over Broadband

 Hello all,

Since this is OT, Personal emails encouraged rich_lavsa at pghcorning.com

Looking for a solution that isn't too expensive and do not know where to
begin to look as there are so many different routers, services, software
packages, etc.. 

I do some consulting on the side, and have been approached by one of my
clients to tie their offices together.  They initially had an outside
company come in and set up their internet services as well as their
network in each location.  Since I've taken over, some things have
changed and they now have the NEED to have their 2 office networks be as
one.  

So here is what we have...

2 offices connected with Business Grade Cable Broadband
Each office is a Workgroup network, no domain exists.  (??might be a
problem??)
Linksys routers (non wireless)
It is a Family Doctors Practice so I don't know if HIPPA comes into play
with this once they are sharing information over a public network of if
we need dedicated private lines because of HIPPA.  

Anyway, Since I know only enough to be dangerous to a network this would
be my first NETWORK CONSULTING gig, I'm doing it for free as a learning
experience for me and for them as they have been great clients for me.  

So here is my question:
1.) Looking for suggestions/white papers, informational sites, books,
anything I can do to learn what I need to know to make this happen.
2.) Advice from someone in the know on how to do this.  
3.) What equipment do I need?  I'm pretty sure I need a firewall on each
end with secure VPN capability, but again I've never set up a site to
site VPN and therefore I'm a little apprehensive about buying something
and not knowing how to set it up, and later finding out I bought the
wrong stuff.  So if anyone could lend some advice on what equipment to
buy and what brands are good for this vs what experiences you might have
had either good or bad.

Rich