Quote from GTS:
Cisco products are rock-solid and if the code tends to be the same between the low-end and high-end products in the same family so if you buy the 5505 firewall you are running the same code as the enterprise class firewalls costing tens of thousands.
IMO you should still run anti-virus even with a firewall, a software firewall is not necessary.
With regard to router vs firewall, a firewall will have all the routing capabilities you need but a router with a some firewall features will not be as robust as a real firewall.
Many folks think that a cheap linksys router/firewall with NAT is all the protection you need. I strongly disagree but this isnt the forum for discussing the technical details of what the difference is between a $30 linksys and a $500 cisco asa (or sonicwall).
So if you are only going to get one thing (which I recommend) get a firewall, not a router.
The device wont care about the type of ISP connection, your ADSL2+ modem should have an ethernet output that you connect to your router or firewall - the device itself will not accept an ADSL2+ connection directly. If you need to be able to team or bond two connections together to act as one you should make sure that the device you buy supports it.
So am I too understand correctly that firewall will do basic routing?
I recently bought a Linksys WRT54GL and installed tomato.
Disclaimer: I learned what I know from telecom sales; VOIP and stuff, that's my excuse, and trial and error while day trading.