Just don't get cable. Cable sucks for trying to run a server, and here is a list of reasons why:
Many major Cable Internet providers (notably Comcast) have decided that running a server (even for non-commercial use) of any kind is "bandwidth abuse" and against their Terms of Service.
Because of this, many users on Cable Internet connections find that such important ports as 20, 21, 25, and 80 are all completely blocked to outgoing traffic, along with several of the higher-number ports used by some of the various non-www internet technologies such as P2P applications, media streaming services, telnet and ssh-type services, distributed file systems, and multiplayer network gaming technologies. While the non-www technologies often offer alternate ports that can go around these blocks, it's generally pretty important to run a web server on port 80 and a mail server on port 25 if you want to keep things running smoothly with a minimum of hassle.
Upload speeds are capped at about a tenth of download speeds, so you get 1.5 Mbps download bandwidth, but only 150 Kbps upload bandwidth, which is, if you do the math, only enough to serve three simultanious 56k connections, at best.
And that's the cap. Since lines are shared, peak usage times often are cause for even lower upload speeds, as well as noticable drops in download speeds - thanks to the fact that the cable companies sell far more bandwidth than they actually are able to provide.
I'd advise DSL for running a server, if it's available in your area, and will likely switch to DSL myself as soon as I get the chance. It also happens to be cheaper in most regions where it is offered - so I think the reduction in download speed is well worth it considering the greater upload bandwidth and degree of freedom with which it can be used.
Then there's the really fun stuff like T1 and T3. Unfortunately, you pretty much have to be a multinational corporation to affort that sort of connection - but they offer a level of reliability and consistency of speed that is unmatched by consumer broadband pipelines like cable. I have contemplated the idea of trying to run non-profit T1/T3 shares, however, and they could theoretically be both cost-effective and far more technologically attractive than individually purchased consumer broadband - but they would also have to reside within a limited geographical region to work, considering the cost of running all of the networking infrastructure. Really, such an idea would be best suited to office parks and apartment complexes inhabited primarily by students and/or professionals.
There's also the idea of root-access hosting to be expored - hosting where you have full administrative access to the particular server responsible for your files (through SSH, most likely, to remove any geographical limitations from such a service) and can thus run server-side applications and such in the same manner with which you would be able to do whatever you want with a machine in your own home - giving you the best of both worlds in terms of infratructure and flexibility of use. It would be more expensive than shared-server hosting, but shouldn't be too bad on the pricing range as server hardware is really the least of your concerns when compared with the cost of bandwidth and infrastructure. To illustrate, I purchased a 2.6GHz Athlon machine from HP to use as my server for under $500. Is is grossly overpowered as servers go, as it is capable of spitting out content at over 100 times the maximum upload rate allowed by my connection - and has done do on many occasions for file transfers behind my router. The annual fees of the only internet service available in my apartment complex - RoadRunner, are in excess of $400 (split three ways, but so is the bandwidth). Using the server at 1/100 of capacity for a single year is almost as expensive as the server itself - and most web servers could get by blissfully on hardware commonly thrown into dumpsters if no one is trying to use them as graphical workstations at the same time.
When I'm accessing my site from outside my network and all-text pages are slow to appear, I know there's something seriously wrong with how bandwidth is marketed and then regulated. 3 KiB pages are supposed to show up almost instantly, even on a 56k. Yet, somehow, they don't.
may seeds of dreams fall from my hands -
and by yours be pressed into the ground.