I take just my Broadband from Virgin and my phone service was provided by BT via a landline.
I've recently switched my phone service to Vonage VOIP using Virgin Broadband as the carrier. I have a 1000minutes a month of free calls at a cost of under £8 /month. Other offers are available. Vonage supplied a Grandstream HT801, which has plugs for both the ethernet and phone ( A Panasonic KX-XTGJ324E) Vonage ported my BT number across and after 6 weeks I'm very happy. - I had to make one adjustment to my Netgear Router and the rest was simply plug and go.
Make sure you have a lowish ping rate on your broadband, ideally around 15msec is fine, but upto 50msec is tolerable.
