Ok I bought the Zotac (with 4GB RAM and 60GB SSD, I guess that RAM would be more than enough, if I need more then I'll buy later). Waiting for deliveries.
Here are things I'm planning to try:
1. Install dd-wrt x86 on it (please refer me other x86 router specific configs/OS if available). Try DHCP and few other settings to single computer.
2. Try adding router instead of computer.
3. If first 2 steps are good, install Ubuntu on it and try to replicate first 2 steps inside VM (hopefully with complete control over networking, 2 CPU cores and some RAM)
4. If successful then I'll use it like that otherwise revert back to step 1.
I wanna try setting Linux box as is as a router but I don't think I've enough knowledge to do this.
I'll update again once I try these.
Nice! Look forward to hearing the results. 4 GB of RAM is plenty. It'll barely use any since the OS uses very little and most of the memory consumption goes to switching and NAT tracking which is still small.
I'd say install DD-WRT or OpenWRT on it as step 1 like you said (I think DD requires a paid license to configure wireless adapters which costs about $21). Personally I think either one is fine, but OpenWRT might be a little easier to install and is modular rather than one static image so you can upgrade easier and add packages for different things.
Not sure what you mean by "2. Try adding router instead of computer". The Zotac will be the router (put the Pace in DMZPlus mode so it bridges to the Zotac. The Zotac will get a public IP and the Pace won't do any firewalling and DD/Open will handle all that.
It'd be an interesting experiment to then put Linux on and virtualize the router software (presumably you want to do this so it can be a router / media PC?). I honestly can't say how that would hold up streaming 1080p video over VPN and then rendering the video under the 2 VMs but it might very well be just fine.
Unless it's purely for educational purposes, there's no great reasons to install Linux and set it up as a router. That's essentially what DD/Open are; Linux OS's with a GUI that make it easy to manage like a router. If you run Linux, you'll probably end up installing some kind of firewall manager to avoid configuring NAT, port forwards, and security rules on the command line. Then you'll need to script something yourself to ensure the VPN connection stays up and drops traffic if the VPN goes down. And then whatever else you wanna do router-wise will be manual and it'll be a bunch of independent things rather than managed from a nice web interface.
On another note, I just bought the TP-Link Archer C2600 to try installing OpenWRT on and see how it does with the VPN. I'll post back when I get it and have some results.