you have an installment sale. even though you would qualify for the home sale exclusion, depreciation taken while it was a rental must be recaptured before the home sale exclusion can be applied. normally form 6252 would be used to report an installment sale. but you'll have no reportable gain, except for depreciation, because of the home sale exclusion. so no purpose is served in reporting the sale on an installment basis.
you do need to charge interest on the $100K. if you don't the IRS can impute interest which means that as you collect the$100K the IRS will treat a portion as interest and the rest as tax-free principal.
