Ear mites can be difficult to get rid of. Over the counter preparations are easier to get and are less costly than the preparations you get from a vet, but in the long run it's cheaper and healthier for your cat if you get a good miticide from a vet. Mitaban is a good one, and it's not overly expensive.
Treatment for ear mites is done in stages. You put the drops in the cat's ear every other day for three treatments (spanning 6 days), wait a week, and then repeat the three treatments spread out over 6 days again. This usually takes care of even a fairly severe case of ear mites.
Ghilly
Depends on what type of mice ya got. I like the little grey fuzzy ones, just put 'em in there and let them go to work! (Sorry, couldn't resist...I love typos!)
Seriously, the best way to take care of it is take him to a vet to get "the shot". It works much better than the over the counter, that are mesy and take many tries, usually.