First, I'm really glad to see you're being proactive about your dental problems. Good for you, you're obviously trying to have better health. Having said that I feel from what you have reported that you're really getting the cart before the horse. In my professional opinion and given the problems you've briefly outlined, at home orthodontic solutions or bite guards are probably the last thing you should consider. In fact any orthodontic care at this point in your care may worsen your problem more than help. This is a complex system and needs thorough evaluation. My advice is to find a thoughtful, well qualified practitioner to help you find out how your teeth got to the position they're in, why you grind your teeth, what you specific aesthetic goals are and what is a very measured, defined and reasonable plan to make that happen.