How to promote a prize fund and sponsored bungee jump together

Hi all

A local business is going to donate a washing machine or other appliance that we can use as a prize. The idea is to get donations and then you can opt to be entered into the prize draw. I know legally all prize draws have to have a no purchase/donation necessary clause - meaning anyone can enter the prize draw without giving a donation. The risk is that no one will donate and someone will get a lovely new appliance. But that is the risk and I get that. My question is, can I promote donations to a sponsored bungee jump along with the prize draw e.g. 'Sponser Mr X to do this bungee jump and you could win a washing machine'. Or should it just be a separate bungee jump and separate prize draw. I am looking at this all in terms of legalities.