Hi there! Yes you use the same form I864. We used our UK bank account, although that was 5 years ago.
I don't know how much you plan on having from the sale of your home, but I just wanted to point out that you will need MORE than the $29,437 for a family of 4 if you are using assets to qualify on the I864. Whatever your income that you use for the I864, if it falls short of the guidelines you need 5x the amount you are short in assets to qualify.
Example, if you make $25,000 you would be short $4,437 and would need 5x that to qualify on your own. So in addition to your income from your job, you would need $22,185.00. It sounds like you plan on all going over together and you won't have a job, so I would think you would need $147,185(29,437x5)
Someone can correct me if I'm wrong, but I'm pretty sure I'm reading it correctly. If you need more in depth help, as this site is mostly for people emigrating to the UK, I suggest looking at
http://www.visajourney.com/ as they have a forum dedicated to DCF and a whole subforum for the UK. You'll get some help from the lovely here at UKY, but Visa Journey has tons of helpful info for US immigration.