I've spent some time reading the threads on this forum, what a fantastic source of info!
I'm beginning to understand more about VOIP but am a bit confused about what I need to buy, I hope someone can help straighten out my confusion

I was sent a BT Home hub by BT for Broadband talk, but as I already have the Buffalo router, I thought there must be a better way and started looking to use that for VOIP. The BT talk person that I waited 1/2 hour for had no clue what I was talking about other than to suggest a 10v converter for my router, ( haven't yet found out what that is yet )- then I came across this forum and see that you really do know what you are talking about
What I have:
2 BT landlines with 2 separate numbers ( and of course 2 lots of rental)
BT broadband( is there a better, cheaper alternative, I notice here that Talk Talk free broadband is not recommended, why is that?)
Buffalo high power router for wireless network
2 sets of cordless DECT phones for landlines, ( one set which I be will replacing with new ones, I need 4 handsets, any suggestions?)
1 Linksys Skype phone ( can this be used with VoIP Stunt or other? )
What I am trying for:
I would like to replace one of the landlines with VOIP ( possibly both in the future, but don't I need a landline for the broadband?)
I read here that I need to buy an ATA: would like one that gives me the options for more than one VOIP phone/number, any suggestions? ( I notice Ivor recommends the Fritzbox, but that seems to have a router included which I don't need ) Other recommendation here seems to be the Linksys/Sipura SPA1001 , would that give me the option to have more than one set of handsets?
need to buy set of 3 or 4 DECT phones ,I read here that it is possible to use the same handset for VOIP and landline, any suggestions as to which I should buy? I need 3 or 4 cordless handsets
Thanks so much in advance to anyone who takes the time to respond to such a rambling post

, you see I'm almost there but would appreciate help in the last step,
Thanks,
Shirley