What firewall solution to get?????

With so many firewalls out there, what one do I provide for my customers. More and more are getting DSL, schools are now required by regulations to provide filtering. Clients are asking for all levels, from simple security to filtering options andanti-virus built-in or available. What I’m looking for is one or 2 products that I can provide that are easy to use and able to scale to each solution. Of coarse, money is always an option that needs to be low.

db