Unsecured Lines of Credit

Here's my scenario. I'm wanting to buy my first home. I'm 26, single, and without kids. My plans are to live in this house for 5 or so years, then when I'm married turn this house into a rental and move into a more "family suited" home. The home I'm looking at is a REO, cheap, and only needs some minor work. With it being so cheap I'm wanting to buy the house on a LOC initially then after a year finance the home under a traditional mortgage. My logic is buy it cheap at a low appraisal, repair/update it, then after a year finance it under a traditional mortgage. A year from now and after repairs/updates it should appraise higher yet I'll only be borrowing the initial amount. So I'd be borrowing 50k on a 75k+ house giving me 25k+ of additional equity. Here's my dilemma, I have no collateral. My family wont cosign with me so I'm on my own. Is it possible to get a 50k unsecured LOC? My credit is good (700 range last I checked) but is that enough?