BT don't do FTTPoD - you are basically stuck with Cerberus or one of the resellers so your monthly price will be £100+vat. You should try and strike an arrangement with your neighbours where they contribute to your build costs - they will then be able to take FTTP from any ISP including BT who are currently the cheapest. By the time your FTTP is built there should be other packages available from Sky, TalkTalk etc.
They'll be able to order if only they're served by the same CBT, which usually means the same pole or the same jointbox. If they are bit further along the road, then even if the fibre goes alongside their property they won't be able to order.
The way to resolve this is to submit linked orders - then the combined order will build *all* the CBTs required, and will be only marginally more expensive in total than the single order.
The downside is all properties will need to pay the £100+VAT rental for the first year - but as long as all properties get their own rural gigabit voucher, that should more than offset it. Given how much grief FTTPoD can cause the CP, I think they earn this money