Lastly what's the better bet, the BB modem supplied by the ISP or go for an internal PCI card one.
Any thoughts or recommendations?
I'd say none of the above. Go for an ADSL router.
It would add more protection from internet nasties by providing what is called NAT traslation as a minimum and probably some more advanced firewall options.
In addition as single port routers are rare now it would no doubt offer the option to easily add more PC's should you ever need to. Even a single port router offers more options. e.g. perhaps to add a wireless access point later - that said a decent ADSL router with wirless is sub £100 now days.
As long as you have an network card in your PC a router is IMHO the way to go.
Memetic.