All of the mods that I have seen that make a grill run hotter affect the entire heat range. If you want a higher top end, you will give up your low end, in other words. What you likely want to do is extend the high end of the temp range without giving up what you have on the low end, and that will involve valving. If it's ok that the grill won't run a stable temp below 450-500F, no problem, bigger orifice or higher pressure reg will get you there.
When modding, the first thing to go will be the low end. What is your lowest temp you can get right now? Get a baseline. How much of the low end are you willing to give up? In the quest for higher temps, most people seem to neglect what it does to the low end. If you don't need or don't use the stable lows, no worries.