40k is a good amount to have saved up but unfortunately you may still be looking at costly lenders mortgage insurance as you're under a 20% deposit. If you could use the equity in your parents home as a guarantee you may get around it, otherwise you could apply for a low-doc loan but the higher...
Your current debts, income, stability of income and savings for a deposit would be key factors in deciding what outlay you can afford on an IP. I'm in a similar position to you, same age and budget for a property, 55k income with a 20%+ deposit.