write all the options down on paper. Pros, cons, advantage, disadvantage etcetera.
The company that is making you redundant - would you be going back for better rate? or are they selecting you because it saves them advertising/interviewing/unkown quantity etcetera.
I personally would treat each job offer on it's own as a completely NEW job. i.e. make your old company pay full wack on your job responsibilities - after all, it's them that gets the profit - right?
Then after all that consideration - tell the new company that you had a two week holiday booked for march and you've had no holidays whatsoever this year. You should then get full entitlement of 28 days.
best of luck.