I've written on this subject before and hope I can offer a balanced opinion.
I had an involuntary break from flying in 2004 and with 4000hrs as an FO couldn't get back into the market. After turning down Globespan, I finally did a self sponsored 737 rating with Excel/XL at GECAT.
The deal then was very clear, we paid for the type rating (at the end) and were paid by Excel from day 1 with the appropriate contract signed in advance.
Unless you are offered a deal like this, then don't even think about it. I also wanted to do a 320 rating in 2004 and to GECAT's credit they wouldn't even take the money as they said there was absolutely nothing out there.
Assuming you go ahead you will be one of countless hundred people hawking themselves from company to company. The only ones likely to be interested are companies that you don't want to work for. Most decent operators want to control their own standards.
The most likely scenario is that you get a chance with one of the turboprop operators such as Flybe or Eastern Airways. They won't be interested in the slightest in what rating you have, and if you get an offer you'll still have a mountain of debt and a worthless rating in your licence.
I now live and work in Germany and it's sobering to note that last year the flying schools here produced 900 pilots! This year there are probably 250-300 jobs available in the large airlines and Lufthansa are about to make up to 200 pilots redundant. I'll leave you to do the maths yourself.
Go and get any job you can to pay the bills. Keep sending the applications and wait for better times. Then go to the pub and reflect on the GBP20,000 debt that you don't have!
As always, the very best of luck :-).
KT