Cisco certs are worth while and respected not to mention it gives you all the basics....
Networking is growing everything runs off IP networks mobile phones, cable television, every workplace....
If you get into the ISP world you will quickly find out companies use multiple vendors Juniper...
Are you part of the InfoSec department?
A network based IDS can be run off a spanned port and at least give you reporting as to whats going on.
I definitely wouldn't use 1 vendor for everything.
You can run it on the same computer...
Just connect to a regular http site while running wireshark stop the capture and then there should be an option to follow a TCP stream and reassemble it...you will see everything in plain text.
Then try it again with SSL site
You should probably setup a VPN.
pfSense/Vyatta and a number of other products will let you setup a site to site VPN they also have load balancing and other technologies on them however you won't load balancing the VPN traffic.