There are three options in scheduling a Mass Intention. The first is to allow the staff to choose the first available Mass. The second is to choose a non-specific time and day. (ex. any Sunday noon mass) The third option is to chose a specific time and date.
A Mass stipend is not required, rather it is a customary offering to the Priest. The spiritual value is in the Mass itself. The inability to offer a stipend should never deter someone from scheduling a Mass.