There is no difference between generics like amnesteem, claravis, etc. Pharmacists will interchange them because they are all the same thing.
The only one out there that may actually work better is Absorica, because it is formulated with an ingredient that makes it absorb better. It is not interchangeable with other brands, and is still under patent, so is a bit more pricey.
Normally Accutane has to be taken with a high fat meal, but Absorica is absorbed even without the high fat. Despite this, there is no research to show that results are better on Absorica, but it is relatively new, so time will tell. I use this brand and it just gives me a bit of peace of mind to not worry about what type of meal I took it with.
Glad you took the plunge! It has been well worth it for me.
And don't sweat the low dose. I am a big lover of this method. There is NO evidence to show that higher daily doses work better, and there are actually a few interesting studies that imply low doses might be better because the length of the course is longer, and longer term sebaceous gland suppression leads to lower incidences of relapse.
Get all types of blistex, aquaphor, a good moisturizer and a gentle cleanser. Drink lots of water and get lots of sleep.
Best of luck with your course.