Building my first PC for a bit of scum.

[JPR]

Here is a lovely story:
I live in England, and am at 6th Form College (age 16 right now) and because I am poor, get £30 ($53.82) a week for showing up to school. So by christmas I'll have over £200 ($358.82), which I will be setting aside to build a computer with. Its a very low budget. and is important that I build a good PC because, basically, my parents are retarded and the last computers we've got have been bought at PC World (very shite rip-off shop) for wasteful amounts of money and poor performance- they don't listen to my when I tell them to shop around, and I can't be too forceful because they are the ones that pay for the PCs. This is the only way I can tell them to stop being such dumb fuckers.

I'm also interested in building a PC totally independent of my parents- I can be free to mess with things like Linux which would be ultimately cool.

I figure some of you may have been in similar situations, and wondering what you did.

Stuff I want from the PC:
>Do college work.
>Internet through dial-up.
>Live a long time- I'm not going to buy a second hand hard drive that dies in 6 months time.
>A small desktop PC (Micro or Flex ATX, Mini-ITX) on top of my desk would be so much better than a tower under my desk. -- BTX cases are cancelled forever, right?

Stuff I don't need:
>Decent graphics.
>Another DVD player for my room.

I am seriously tempted to build a Mini-ITX- super quiet or even fanless for nights I stay in and am up late. Also would be an interesting build.

The PC I use right now is a laptop, 2.6 CPU, 256 RAM and don't want to make a £200 copy of this from sub-standard parts in a regular case, thats why I am looking at small form factors. Although am tempted at the new AMD Sempron technology, but speed is unnecessary to be honest, just I know this tech. will last a long time.