Hi Andy,
You might be better asking this question on the Professional Pilot Training forum under the Wannabe's section. Those who have already gone the modular route might offer more experience.
That said, I'm sure White Waltham will offer you excellent training but you might find that you benefit in the long term by starting out at a field with formal ATC and a busy mix of commercial and GA traffic. White Waltham is always busy on a sunny day but it's easier to work back towards an FIS/Grass airfield environment rather than upwards to concrete runways and jet traffic.
Good luck with your plans whatever you choose.