I sure the career development loan is available, as my flight school in Florida was registered and the maximum loan was £7000 which just covered the CPL/IR conveniently! I was informed this half way though my multi engine skills test!
I hear the professional studies loan offered by HSBC is now not available for pilots, or will soon be made unavailable. I've seen a similar thing with Barclays, but I don't recall seeing pilot being an acceptable profession.
Im not sure of your own situation, but I went to University, lived at home, and saved my student loan, so I got a cheap £10,000 loan. But I still require a commercial bank loan for the rest, which I think will be hard for me given my situation.
You might want to try your local educational dept. I doubt many will give out the money, but your LEA might do.
Other than that, Northern Rock has a typical loan for £20,000 at 5.9%, unsecured. In terms of interest free during training, some banks will give you a payment defferment until about 2 months (possibly more) which is just enough time to get a CPL/IR if you're lucky.
Good luck with your studies,
Alex:-)