Does Our Small Office Need a Firewall/VPN Hardware

We are a four person office with a Verizon DSL connection to the internet and we have a Static IP.  For many years we have had a Cisco Pix 501 installed between the DSL modem and the the outside internet. We want to switch over to Business FIOS to get better speeds and also we will be migrating to a virtual PBX system.  Most of the state of the art firewall hardware out there is expensive and while I am somewhat knowledgeable, I am not qualified to install such hardware and configure it properly, and so we will have to hire a network consultant.  We also do not have a dedicated server, and operate on a peer to peer basis with my computer acting as a server surrogate.  So my question is this: do we really need to have firewall hardware?  Accessing our system from the outside works quite well with GoToMyPC, so a VPN is not really a necessity.  In addition, I am assuming that the FIOS modem/router will have built in firewall protection which may be perfectly adequate for our purposes, and we could install additional protection with a software based firewall system.  Am I right?