when calculating your toatal mortgae payment you will need to take the amout financed and multiply by approx 5.75. Then take the yearly property taxes, divide by 12. Add in approx 60 a month for home owners ins, anoither 60 month for PMI (mortgae insurance) an dthen add those up. On this particualr home, if you FHA, you should be around 1250 month total morgage payment.
Also, the very first thing you need to do is get pre-approved by a local lender (I have several good ones). Your REALTOR should be able ot reccomend one. Your morgage lender will be able to provide you with a "Good Faith Estimate" which is a very detailed breakdown of the monthly payment, along with a breakdown of required closing costs.