Building a multipurpose computer

hello.
I'm planning to build a multipurpose computer which will be a ASDL+router+firewall, boinc crunching machine and HTPC. (don't mind the balance, I'll take care of it)
planned rig is has followed:
cpu: Athlon X2 4400+
mb: ASUS M3A78-EMH HDMI + O/B ATI HD3200
mem: 2x1G
tv tuner card
hd: WD 1T
the rest I have.

now here are my questions:
1)I don't have a hd tv (no money) so I'm thinking of doing this:
- getting a vga/dvi to s-out converter
- using a old radeon 9250 card which I have laying around till I'll be able to get a better tv
- getting a no O/B card mb, using the old radeon and getting a better card later
now I read the TH's article on building a HTPC, that is why I want that board, what performance impact can I suffer if I take the third option? (getting a mb with amd chipset) which option is best in my condition?
2)can someone recommend a good (and not expensive) tv tuner card that is pci and is supported under linux?
3) has I understand it, when getting a feed from the antenna of the tv tuner card, the signal is transported directly to the graphics card, right?

I need to stress out the fact that I need to lower the cost of building the system has low has possible but on in expense of quality.

thanks in advance.

1) the built in gfx will do better than that radeon, in fact swap that board for a M3A78-VM, you get displayport, DVI and VGA out, and you can get dp to HDMI and HDMI to s-video connectors.

2) to be honest you should get a nice 28" HannsG tv before you buy a HTPC, they cost about $335, are 1920x1200 with 1920x1080 scaling, have composite, component, a few HDMI and some other ports so you can use it with older goods too.

one more question, what quality of viewing can I expect if I use the old radeon 9250 card until I get a better tv? (no HD)