OK, here goes:
1) The PIX is a dedicated firewall. That is its only purpose. (well, not technically, but still...) It isn't really a router. Also, the PIX is End of Life, and is no longer made by Cisco. It has been replaced by the ASA, Adaptive Security Appliance.
2) Cisco routers can be a firewall, through the use of things such as Access Control Lists, route statements, and other config methods. It also, obviously, is a router.
Best security practices generally call for having both. Having one device do everything is dangerous, since if it gets compromised, your network is wide open. Defense in depth is the key here.
The problem is that, as Sesshi pointed out, if you don't have IT staff that know Cisco, dealing with Cisco can get tricky. I am Cisco certified, and deal with it on a regular basis, and the sheer number of configuration options still gets confusing to me. I often just call our Cisco reps and tell them what I want to accomplish, and have them work out part numbers, models, etc.
I used to work at an IT consulting firm that specialized in small business. We sold and supported a lot of Cisco stuff, but we also sold a lot of Sonicwall firewalls. For small business, their lower price and complexity often tended to be a better fit. There are some other brands that offer similar capibilities for a lower price.
Edit: I forgot about the newish line of Cisco products aimed at the SMB market. It's the "Smart Business Communication System". It's a range of products aimed at small businesses that have limited or no IT staff. They are easier to setup and cheaper than the big boy Cisco routers and ASA devices. Here's a link:
http://www.cisco.com/cisco/web/solu...art_business_communications_system/index.html
Another:
http://www.cisco.com/en/US/products/ps7293/index.html