ISP for student flat

I need to setup a broadband connection for my bro's student flat in Cambridge, the basic requirements would be: £15pm, 2MB downstream, minimal contract length (since he'll be there for 6 - 8 months).

The landline in the flat is not activated, I've had a look at virgin media who provide cable broadband in the area, but according to the details for their basic package they require a Virgin landline, which bumps the cost up to £24.50pm.

So would it be a cheaper option to rent a BT landline, and find a cheap ADSL provider? BT seem to have connection charges and minimum contracts which makes it all a bit trickier to figure out

Best performance , no throttling, no traffic management, true unlimited
Post Office phone line which is on a monthly contract. Their installation cost is lower than BT.
Pricey Be Broadband Unlimited on the three-month contract option. See MKD's Net Costs document for details. Note the current £40 cashback available from Quidco (top quality but take the first £5 in a year of the total cashbacks a user gets) or TopCashBack (reliable and don't take an annual sub).

Budget price, good quality but see below, can supply line as well, 10-day contract if setup and optional router paid for
Plusnet. Drawbacks are the traffic management and the fact it is BT Wholesale based, unlike the Be Premium above. Against that, there is an unlimited night-time period as well as the metered peak time allowance.

cheers for the info, I'll have a good look at 'em and see how I get on