New router with wireless N (preferable with GigE ports) that will not conflict with my network?

New router with wireless N (preferable with GigE ports) that will not
conflict with my network?

I have two internet where each have its own modem, one 3com 5 GigE ports
unmanaged switch, and 1 D-Link 524.
This is my network setup:
One internet directly connected to PC 1.
One internet directly connected to D-Link router.
D-Link router connected to switch.
Switch distributes local network accessibility and internet to all
computers connected to it.
Switch does not distribute internet to PC 1 only local network as I do not
want PC 1 to use the 2 internet.
The above works great with my D-Link, internally on my network I also use
a set of things for example:
I have my own server that deals NAS, development server (MySQL, HTTPD,
SVN, etc) and a set of VM's that are connected to a external OpenVPN
Server
I have other 4 computers that are mainly personal for navigating or
playing games mundane things in general.



As I mentioned for my current setup the above works great I have no issues
at all however my D-Link is damn old and I would like to upgrade my
Wireless to N.
So I got a new router NETGEAR WNR3500L-100NAS however that router was a
huge failure on my network.
It would conflict with all my VPN's not allowing it to work perfectly
dropping the connection constantly, it would drop my notebook connection
constantly, it would hang my network internet constantly.
I have tried several different solutions:
upgrade firmware
strictly setup the router for my needs
wide open setups
different recommendations from their own forum
reset the modem
have tried the VPN options to pass-thru
Pretty much anything available and nothing worked out to fix the
intermittent connection drop.
After a week of trial and error I finally gave up on that router and
returned it to the seller, however I have not given up yet and am still
looking for a new Router, and now on I read a lot of the qualifications on
newegg before doing so, however not all are useful.
So here I am asking all super users if they know of a modem that will not
yield such problems or incompatibility with VPN's that you can recommend
me to try/buy?