Technically speaking, I don't think it's possible. However, you can get the maximum effect out of your stats. For starters Agility becomes irrelevant in terms of affecting your CTB speed at around 170 points. For another thing with maxed out Luck (255), you can automatically hit any monster and need only about 25 Evasion to evade anything that isn't auto-hit. Whether or not this will allow you to reach 99999 HP and 9999 MP is another matter, because it's common for players to simply have MP at 999, since there's very few reasons to have anything more than the base maximum, especially when you get can get hold of Three Stars.