I am going to assume that you are talking about the home tax credit.
You must not have owned a home in the past 3 years and purchase the home this year. A manufactured home does qualify if it is attached to the property, property tax wise.
Now to finance a manufactured home this way you will need to go FHA and have it meet the FHA standards as far as the way it is set up. You will need a Realtor that is familiar the the requirements, do not just buy a For Sale By Owner with out at least checking with a mortgage person about the particular home first.
And please do not beleive all mobile home sales persons, their financing is different. You will need this set up in order to resale when the time comes.