Well unless you move to a fully unbundled service like TalkTalk you're going to need a BT line of some sort, even if you don't pay the line rental direct to BT. However by looking at bundles only you're severely limiting your options when it comes to broadband. If you really don't want to pay BT for rental pay it to the Post Office instead and you're leaving your broadband options open.
Newnet Home Lite would be the pick of the bunch for 3GB usage or under. They will give good service, support is UK based and comes with a 1 month contract as standard. They may offer the option of a fixed rate 1Mb line rather than ADSL Max if your line is not great.
ISP newsgroups offerings tend to be very poor if indeed you get them at all; either the retention will be low and/or downloads will be rate limited. Why not consider a premium news service. If your downloads are infrequent paying a monthly subscription does not make a lot of sense so I use a block account from
Usenet-News so I buy a 100GB block for $24 and that can last for months so it is a very cost effective way of going about things. If you only want text newsgroups Google is as good as any.
Another good one to consider is Entanet; they offer a 3GB peak/30GB off peak product at �16.50 a month, but they definitely offer 1Mb fixed speed lines and a text-only news server. Like Newnet they have 1 month contracts, and excellent UK based service. You might read about peak time slowdowns on Entanet but if you have a 1Mb service you will never notice the difference. Entanet resellers include ADSL24, UKFSN, Vivacity and many others; they don't sell direct to the public.
Regards,
Steve