I use an ATI Radeon HD 2400 XT graphics card (about £10 on Ebay) and this modulator
http://www.earlytelevision.org/405_modulator.html
Hopefully that will look less intimidating as a project, and you could tackle the sound and vision parts separately if you want.
No expensive crystals to buy and no frequency synthesis, just a pair of free running oscillators, but it is quite stable enough, picture and sound are excellent.
I didn't bother with a custom PCB I just used perforated project board.
The chips are still available from Littlediode.