My current system from memory as I can't check at the moment is: Winfast motherboard, 3Ghz AMD Athlon, 2gb ram, 100gb hdd and 128mb nvida gfx and stretching my memory a random brand 600w psu. It was original my pc but has become the family pc now so my idea is leave it as it is and get a new machine for me.
I understand your point of view regarding optical drives and hdd etc but I was planning on taking my dvd drive and nearly all my personal documents are on my external hdd anyway but its almost full so I don't mind more storage.
In terms of building a pc I have no problem putting one together but I am a complete newb when it comes to parts. If I was building it, the minimum I could get away with would be: Case, PSU, Motherboard, CPU, GFX card, Sound card, Network card, CPU cooler, Fan(s), thermal compound and hdd. Taking my dvd drive would do and I could always pick up another in the future. I think that is everything I would need though but as for what actual combo of parts to get in my budget I have to admit I have no idea.