contract to sell and deed of sale

Magbebenta po ng lupa ang nanay ko. Magbabayad ng 50% ang buyer then mag eexecute po kami ng contract to sell since yung 50% ng balanse ay payable within 12 months. Pero ang gusto po ng buyer ay mag execute na rin ng deed of sale pag nagbayad na ng 50% para daw for transferring the title purposes since inaabot daw ng 6 months bago mapalipat anf title. Wala daw po silang kukuhaning documents sa amin at kami daw po bahala mag lipat. Magbibigay din po sila ng 12 checks for the remaining balance ng buyer. Tanong ko lang po na kung sakaling hindi ma honor ang check for lack of funds dun sa iniissue nilang checke, may right pa po ba ang seller sa title? may bisa pa bo ba ang conditional sale kahit may absolute of deed of sale na?

i recommend you just have a contract to sell so that the title is not transferred until full payment. your risk if you allow the transfer of title