Sharing ADSL

Just looking for a little advice really..

I've got broadband (BT/Yahoo Broadband package - I'm in the UK) which works fine. The problem is The ADSL modem that came with the package is a USB only one, so needs to be plugged into a PC.

I have a small home network (3 PCS) And I've got it all happy (for e-mail & Web anyway) using a small proxy server program. The only problem with this of course is that the PC with the modem plugged into it needs to be on & connected in order for the others to browse/check e-mail.

I would like to get some form of router connected instead, so I think my options are:

1) re-configure one of my PCs (I don't use it at all really) to be 'always on' and plug the modem into it. This would mean getting a new motherboard (current one's a bit flaky) and making it fanless/use very quiet fans for near-silent operation

2) find a router which has a USB input to plug the modem into (such as <A HREF="http://practicallynetworked.com/review.asp?pid=427" target="_new">this one</A> ) but these seem very rare..

3) Replace the existing modem with a router with a built-in modem, and plug that into my current network hub, or get one with multiple RJ45 ports and replace my current hub.

Any thoughts you guys? I know I DON'T have a fixed IP for my broadband (i've verified myself it changes each time I connect), if that makes any difference. AS for my own abilities, I would say I'm reasonably advanced with regards to networks, tcp/ip, etc, and quite capable of learning what I don't know.

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Epox 8RDA+ rev1.1 w/ Custom NB HS
XP1700+ @205x11 (~2.26Ghz), 1.575Vcore
2x256Mb Corsair PC3200LL 2-2-2-4
Sapphire 9800Pro 420/744

I have a strong suspicion that they'll have no other options.

I might have to give it a go I guess.

IF I was to just buy the cheapest combined modem/router I could find, do you think I'd have any specific problems setting it up though? I assume I'd have to assign it an IP on my network (or re-assign all my current IPs to be in it's address range, if it comes with a pre-configured IP addr)

Maybe I should steal the Router we use at work over the weekend and see if I can get it working

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Epox 8RDA+ rev1.1 w/ Custom NB HS
XP1700+ @205x11 (~2.26Ghz), 1.575Vcore
2x256Mb Corsair PC3200LL 2-2-2-4
Sapphire 9800Pro 420/744

Sadly I've had to put my plans on hold for the moment... Lack of cash means I can't really justify splashing out now.

That router still requires a modem with an RJ45 connection rather than a USB one - that's why I was wondering about replacing my USB Modem with another one with LAN, but it all adds to the cost

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Epox 8RDA+ rev1.1 w/ Custom NB HS
XP1700+ @205x11 (~2.26Ghz), 1.575Vcore
2x256Mb Corsair PC3200LL 2-2-2-4
Sapphire 9800Pro 420/744