The requirements for a CPL (via the modular route) include having 100 hrs P1. So that's where most of your catching up will be. The PIFG counts for nothing unless you've complete the JEFTS ground school - and then it gives you an IMC rating.... but UAS studes don't do the JEFTS groundschool until after IOT.
JAR also acknowledges that the military only log flight time, so they give you a "chock-to-chock" allowance. Unfortunately for EFT graduates with lots of 1 hour flights, the allowance is strictly 5% of your total time (great for the VC10 and tristar mates though!).
To qualify for your PPL, you will need to convert to type, complete the qualifying cross country (which you will have to do dual first too), and pass the skills test. As BEagle suggests, if you can find a G115, Firefly or Bulldog to fly, this shouldn't take long - I took 20 hours, but did a lot of "solo consolodation" whilst waiting for weather good enough for the QXC. (Damn annoying when you've got a PIFG!)
Talk to a number of schools (trying to stay local), and see if they have any ex-RAF pilots or QFIs. They'll understand what you've done far better than a civvie instructor.
After you PPL, spend some of your budget buying into a group-owned aircraft. The flying is the cheepest you'll find anywhere, and it gives you the freedom to take the aircraft away on long holidays and adventures for very little cost - unlike hiring, where you can bearly afford to go away for a day, let alone a week. Whilst many groups stipulate 100hrs P1 for insurance purposes, our insurance company waviered this when I told them that I'd done 88 hours dual with the RAF!
Also, as soon as you've got the PPL out of the way, and have found that golden aircraft share, get yourself enrolled on to a ATPL Groundschool course. The work is hard, and if you have a day job, it will take you between 6 months and 18 months to complete. By then, you'll have exceeded your CPL minimum hours requirement having taken every member of your family and village up for AEFs!
If you want to join the airlines then you will need a CPL AND IR. Budget to spend at least £20k on these alone, and you won't be too surprised when you go over hours.
Alternatively, if you'd like to hang around the light aviation scene for a bit, do the FI (flying instructor) rating and "use your head". ho-hum. The pay is ****, but you'll be able to build up your hours and learn a lot about human factors in the meantime!!!