With your score you are on the line of prime and subprime! A good loan officer will look at you credit report and look at all the options. Most loan officers take the easy way out and the easy way can pay them more and cost you more!!
They need to try to take you Alt-A or get an uplift to go Prime. If I were you I would pay everything on time and put the 20K in the bank. Go prime they are going to ask for 3 months of you bank statements to show that the money has been in your account or to get around that tell them to do a Verification of Deposit.
To get the uplift to take you prime... Min of 2 years at the same job or field, No or Paid collections, no liens, and No BK. If you do have a BK you can get around it to go prime. The loan officer just needs to know how to get through and not around the guidelines.
I use to work in a special department where I would under cut and out smart other loan officers. I out smarted them by showing the borrower what was going on and how to read the doc's. In that department I would see HUDs from other companys all day and see all the bull$hit and just break it down for the borrowers. Now im just going blah...blah... blah...
My point is take good notes!!! Get the loan amount, rate, term, and payment before taxed and insurance. Ask about prepays and keep asking till you run out of things to ask!