Your router has firewall/NAT support, no worries there. As such, it's not even prudent to keep a software firewall, the routers SPI and NAT capabilities are top notch, it doesn't really need "backup". I'm using a BEFSX41 router over here, and have decided to disable Comodo, my software firewall.
It looks like virtual server is the option of port forwarding on that router. You say he enabled it, did he open certain ports as well? He could've simply been Port forwarding a couple programs, though i'd really suggest you make sure he opened ports that are needed open for your programs.
Paid for for software is almost always better than free varients.
But with the OP's hardware firewall, I really can't see myself recommended him to pay for something he already has.