It really depends on the current job and your previous jobs or education. I would start however by getting a copy of your credit report from Experian, Transunion and Equifax and see why your scores are low. You are entitled to one copy from each once a year. There are a number of things you can do to improve your scores which increase the likelihood of approval and improve your rate. You can dispute derogatory reports and pay credit cards balances down to 1/3 of their limit. Do not close any old accounts; this will lower your scores even more.
Your current scores would be acceptable to many FHA lenders; Wells Fargo is currently offering the lowest score options I'm aware of.
Best of luck.