What Serial board should i buy? Can i use other pr

First of all, i need an extension for my PC to provide the parallelport. I have a mini-itx board from gigabyte. It provides alot of USB-ports (USB3.0 x 2 and some USB 2.0), however, i read that USB is not that good for anything real time. So, thing is this.. I have one PCIE x16 2.0 to use. That's it.

I had a quick look on eBay and found lots of PCIe Parallel port cards for $2 (+ $2 shipping) so that seems like an easy solution.

Also, since the PC is being used for everything related to computing in my appartment, i would also like to know if it is adviseable at all to run EMC2 of such a machine? - i regularly use boxee and makemkv to store and watch my movies on the TV. In addition, i use it to backup my laptop, PS3 and STB and i am thinking of using it to host a website. Can all this be done at the same time?

In theory, yes. But you are probably unlikely to be doing CNC machining and watching a movie at the same time anyway. Having EMC2 installed doesn't stop you doing any of that. The web server might get a bit slow when EMC2 is running, but EMC should always be able to take CPU time when it wants it.
Unless you are committed to Kubuntu I would suggest a re-install of EMC2/Ubuntu from the LiveCD, it will save you a lot of configuration issues.

Finally, how does mach3 compare to EMC2? - some say mach3 is a copy of EMC, and some say that EMC2 is faster, albeit less feature rich and non-supported. I installed the trial version of Mach3 on my laptop and was blown away by the clutter of guages, buttons, drop-down menus, more buttons and more gauges/plots. Can anybody tell me what the differences are, and whats what? I'm new to CNC and need to learn one of them, so i have no preferences.

EMC2 has a much broader feature set than Mach3. It runs lathes well, it will control 5-axis machines. It will control industrial robots, automatically converting joint rotations into Cartesian coordinates. One big difference is that EMC2 will control servo motors in closed-loop feedback, whereas Mach3 is rather focussed on stepper motors.
I think that Mach3 is probably easier to configure, but with the EMC2 configuration wizards it is pretty easy to get a working system. EMC2 allows you to get into the inner workings and you can set up really quite elaborate configurations that would be a challenge in Mach3. (I have set up gear hobbing and non-circular lathe turning just by playing about in EMC2s Hardware Abstraction Layer, which allows you to connect any inputs and outputs to any other outputs and inputs, via any function you can find in the library, or, in fact, any function you can write).

EMC2 is undoubtedly more work to learn, the payback is huge capability and flexibility.

I would question that Mach3 has better support too. You can contact other EMC2 users and many of the developers 24/7 on the #EMC channel. I have seen problems fixed with a new software release in less than an hour.

so i thought i could just install Kubuntu as it would not be much difference. Hmm.. what configuration issues are you talking about? - any link so i can read it for myself?,

Perhaps i can just install KDE on top of gnome.. That should work, right?

Regarding the Serial port.. is this one ok?
cgi.ebay.com/2-RS232-Serial-Port-PCI-E-E...6b2589#ht_3065wt_908