I need to purchase a conversion kit for Emperor Gas grill. Does anyone know where I can find one?

Hi! I am not sure exactly which model number of grill you have, its always best to start at the manufactures web site first and then go from there, or the store where you purchased the grill. If you can't find it through the direct brand,  here are the web sites I think you may want to look at.
First, Amazon has a large amount of conversion kits for natural and propane gas grills. Usually you can find one here for a decent price.
Next, I would look at applianceworld. They carry a large selection and many fit several model types by several manufacturers.  
Finally, I think that Grillpartsearch may be the destination for all your present and future grill needs. I hope this helps and you are able to get back to grilling again soon! Have a great day : )