Hi Harry
Don't want to leave you hanging with no response, but I'm not quite sure what you are looking to do - do you already have SLR 700s perhaps with a stem mount? Are you planning to mount them directly to your splash shield behind the bumper, or are you looking to make brackets that will then mount to your splash shield? I have the smaller SLR 576 spots mounted on a chrome badge bar that has brackets already welded in to accept these lights, and this badge bar then bolts in behind the bumper guards. I don't know whether the SLR 700s have the same dimension stem as the SLR 576s (5/8 inch), but if they do, that would be my preferred method of installation. A badge bar will run you about $75-80.
This may prompt someone else to respond with other suggestions.
Dave