Right, a wide choice, as FTTC is giving a maximum and ADSL2+ is probably going to be decent.
As MrSaffron says, unless you go for an ISP that will do "Expedited installs", with "SIM(ultaneous) Provide" you have no chance before Christmas. That puts you into a high initial cost even if it isn't already too late, but also a high monthly rate.
Sky and TalkTalk are both full LLU which is fine in itself but can make leaving them a bit less easy as you will not have a "BT line" which all others need.
I think all ISPs allow a free house move within contract but some require a restart of the contract.
If you go for FTTC then you need to be careful when you move again, as if the new area isn't FTTx enabled, (not all are according to samknows), dropping down to ADSL2+ at possibly a very low speed could be a nasty shock. Research the next address as we just did before deciding whether to go there or not.
Apart from Sky and TalkTalk, for cost your best two are BT and Plusnet. If you don't go for FTTC I would say Plusnet. If you do go for FTTC I'd say any of the four would suit, but if you are all sport fans BT and Sky probably the best.
My broadband basic info/help site - www.robertos.me.uk
| Domains,site and mail hosting - Tsohost
Connection - Plusnet
UnLim Fibre (FTTC). Sync ~ 57.1/14.8Mbps @ 600m. - IPv4BQM
"Angels can fly because they can take themselves lightly."
- G K Chesterton.