Mint 0% offer + increased limit

nzmegs

Ok this is longwinded but i hope someone can help:

We have around £18000 spread over three cards. By moving the money around we managed to get our mint card down to around £2500 (as it was the highest interest rate we wanted to pay it off asap).

Today i have been sent a letter saying they have increased our limit to £8500 and are offerring us a 0% transfer up to that limit until Feb 2008 at a 3% fee and thereafter 19.2%.
On the same letter is another offer of 7.9% fixed on balance transfers until the balance is paid with no fee.
I can also use both these offers by doing two seperate transfers if i want. the offer is open until 29 August.

Our other two cards are Halifax with a life of balance rate of 4.5% with a balance of about £8000 (we only pay the minimum on this at present)and Abbey which has two balances one at .9% (about £1500) and the rest at 18% (£6000) - obviously the lower rate balance will be paid first by Abbey. We transferred this from Mint quite recently taking advantage of an offer from Abbey.

What is our best option?
transfer back from Abbey to mint at the life of balance rate or transfer as much as we can afford to pay off by feb using the 0% option and the rest at the life of balance rate? Transfer the Mint balance temporarily to another card and transfer it back taking advantage of the offer? (would we have time to do this?)
how do we best take advantage of this? Are we right to leave the Halifax where it is due to the good rate we have with them?
Help!

P.S We have tried to get other 0% cards recently and been rejected as my husband changed jobs to a lower paid one. we have an excellent credit history and never missed payments but a lower income than before. we have a plan to have these cards paid off in about 3 years by paying around £450 PM (more when possible)and snowballing them, but any advice to speed that up would be great.