All depends on 2 things:
1) How much spare time you currently have
2) How many hours you're willing to put in per week.
I've just passed my test this week after 8 weeks with A Class. I did actually do all of the lessons in 4 weeks, however didn't pass the test until 3rd time round and there's about a 2 week wait before you can take your next test, so half that time was spent just waiting for the next test to roll on. So whatever timescale you do it in, I'd suggest at least allowing 2 extra weeks in case you don't pass first time, as many people don't.
If it sounds good I'd recommend googling their website. Then go to the intensive courses page and pay for it all in a block (I booked the 35 hours for 692, 62 of which included the first test fee). Pretty sure you could ring them and tell them you wanna go intensive but pay per lesson, not sure though.
Once you've paid you'll be contacted by someone from the office to get an outline of what timescale you're working with and book you an instructor. The instructor will then contact you and you'll work out a schedule. I started with 2 hours a day, 3 days a week, and gradually increased over the 4 weeks and did 3 hours a day for 4 days in the last week. Seemed daunting at first but the 3 hour lessons were perfect; just as I felt like I was starting to get bored, the lesson would end and those 3 hours went really quickly. Doing a few days per week also keeps you from going a bit rusty.
I think you have to pass your theory before you book these lessons if it's gonna be done quickly. Probably worth ringing them up and asking. Even if so, not sure what your current situation is but you could maybe book the theory in 2 weeks and study your arse off for it until then, that's how I did it.