Choosing the right firmware

I have read quite a few threads and are none the wiser. I need advice and opinions.

I bought the WNR3500L as a replacement for Firebox X Edge firewall.

My old firebox are unable to handle higher speed than 10/10 Mb/s and due to overhead throughput seems to be limited to 6-8Mbit/s. At the moment my ISP delivers 20/20 but are proming 90/90 in the near future.

I have four windows servers in my network and two workstations and a NAS.

I run a webserver, FTP server and a gameserver.  The gameserver supports a 3D First Person game and latency are of an issue for a good experiance.

I value stability, low powerconsumption, VPN, loggin, GUI and good firewall administration.

For me good firewall administration are the ability to open and close for rules without deleting them ;-)

Can I have all this?

Without a deep knowledge of linux code?

Are there a firmware with theses feature?