70993 Logo Design

I need a logo designed for an Engineering Company. It needs to be a high quality and ORIGINAL design. This is for a client of mine so I need to have all rights to this design and it, and any mockups, must never be displayed in any portfolio or on the web anywhere. Basically what I need is to have the artist deliver to me the logo and then delete it and all mockups from their computer permanently. What I need is to have at the least 3 (4 or 5 is better) mockup designs in photoshop and then they will need to be emailed to me. At which point I will discuss with my client and then get back to you with design changes to the selected mockup, or possibly request additional mockup designs. I will pay ½ of the fee upon to receiving the mockups and the remaining fee upon delivery of the completed logo.