First off, video cards do not improve rendering time unless you are using a special program like RTsquare that uses the GPU on the card to help render. They do help for real time display and panning and moving around your scene as you are working, they just don't affect rendering time. Secondly, I believe currently that Maxwell doesn't support network rendering, you can render out on multiple machines setting the 'seed' numbers to be different and then combine the MXST? (not certain on the file extension off hand) files and supposedly get a higher Quality rendering, but that is multiple computers with multiple copies of Maxwell rendering independantly and then combining the information.
Networks and rendering farms, personally I don't get consistant results, they will work and then they won't, I think if you have a dedicated server that they are reliable, if you have several computers networked together with no deidicated server, it seems problematical.
My personal opinion, invest in a fast Quad (dual dual-core) machined strictly for rendering and don't load a bunch of junk on the machine, just your 3D software and resources and let it be your dedicated rendering machine. I would get a system with the Vista upgrade option with 4 gigs of ram and open ram slots leftover so that you can dump more Ram in once you have the new operating system installed. This way you aren't using any proprietory rendering cards or dealing with network rendering, a self contained beast to do your bidding.
Realistically if you don't like waiting around for renderings, then don't use Maxwell, on a dual cpu Xeon machine, I still leave it to render for 48 hours for final images, I bet a super computer at Nasa would still take a few hours for a good rendering of a semi-complicated scene. If you think a render farm, rendering card or super fast computer is going to render out of Maxwell fast, you are kidding yourself.
Of course these are just my opinions