You can find ultra balls in Cinnabar Island and Indigo Plateau. Some may say that you can find them anywhere after you beat all the Gym Leaders, but I have my own Fire Red and I checked and confirmed it is false information.
You can either find them in certain caves or just buy them at Pokemon marts in the "advanced" places (where there are stronger leveled Pokemon)
u can buy an ultra ball in sootopolis and then u can buy them anywhere after that
You can probaly catch him with a ultra ball but I would use the master ball
Put it to sleep then use an ultra ball.
Pokemarts.
yes u can, that's whut i did and now i have a moltres
No.. However you can soon afterwards. there are 2 oppurtunities for you to catch snorlax. buy u balls in celadon and try the snorlax outside the cycle road
You can buy them anywhere, but you have to beat some gyms. That makes the Pokemarts get new items.
No, you do not need a master ball, if you get it to a low enough hp, you can catch it with an ultra ball. You can find mew in the end of the cave in cerulean.
To catch an articuno with an ultra ball you have to lower it's HP and put it to sleep... To catch a moltres you only have to lower his HP then use an ultra ball... To catch a zapdos a master ball is required... Or you could get a gameshark!
You can buy Ultra balls from any Pokemart after you defeat the elite 4. The cost £1200 each.
Yes you can but it was so difficult for me to capture him but i did capture him with my Ultra Ball but just in case BUY A LOAD OF UM ! I hope this helped!