Most BTL needed a 15% deposit as far as I am aware?

On 90% LTV:

 On a 25 year mortgage = £1818.77 (6.0%)

On a 25 year mortgage = £1923.73 (6.6% - more likely) Total amount payable approx £577,119

Void months etc - you may have 1-2 rooms vacant for 2-3 months or so. could you cover the additional payments on the mortgage?

IMO I think that if you do get a mortgage you will pay over the odds because of your financial status (no income) and this would be a high risk.

If your adamant on  BLT, I would suggest you try something cheaper or perhaps wait until you have a job.

Best of luck whatever you do