Purchase Agreement Needed

We are about to sell product from [login to view URL] We need a purchase agreement. Where people are ordering buy the container we will need 50% down 25% when it lands in the USA and 25% 30 days following delivery to their address. There can be left blank in the agreement so that we can change each one. Where people are ordering less than a container load we will want 100% payment upfront. Inland shipping costs will be extra so we need to note how much this will be in the contract contract to be under California law. Other usual terms need for a contract will be needed. Needed urgnetly. I expect to be able to review and make comments not to be presented with final edition. I would like the contract to be short and sweet.