Sorry if this is a silly question asked 100 times before... but

We are about to remortgage, and it's looking likely that we are going to move from a Lloyds tracker, to Britannia's 5 year fix at 2.79%. I've run through and got the quotes etc... the thing is (and I'm sorry if I'm over thinking this) how much do I ask for? It's probably going to take a few weeks to sort out isn't it? By then we would have paid some more (albeit, only a couple hundred pounds) off the mortgage. So do I ask for what my mortgage statment says I owe now, and they'll tie it up later, or do I work out what we'll owe in a month's time (or two, depending on how long it'll take to sort out) and ask for that.

I'm sorry if I'm making this too complicated... I've got myself in a right pickle over all of this.

Does any of this make sense?!