BEWARE of tank seal kits, ALL of them...use at your own risk A good consistent % of people have these fail, even if you follow the instructions, or go above and beyond. If the lining kit screws-up most likely you will be better off getting a used gas tank and starting all over. It becomes a real mess.
Even if the lining looks good and you feel successful, weeks, months, or even a year or so down the road after normal use (especially with ethanol now in our gas) the lining can start flaking. I've seen this first hand on other people's bikes.
I much prefer to find a local or even over the internet professional place to line the tank. Call paint shops, powder coating shops, radiator shops, etc and see if they do it, or if they know anyone that does it. Usually it's not much more expensive than the do-it-yourself kits!