Leveling 5 toon take about a month and one week if you level up normaly. The daevanion armor can easy last till 45,46. Those stat are awesome and you save tens of million of kinah.
About leveling to 50 in Aion, that a another story, if you have the strenght to reach that level, it could take easy 2 month to level up 45-50. thats only 5 level and i havent count the time to do level 1-45. Maybe 2 month we would say, if you are a casual player.
We are level(Aion Gold) 47 ranger and having nearly 100 million xp to reach 48 and playing time to time without beeing sick to grind like a bot for hours on elite lepharist. It take far more time to reach 50 to level up 5 toon to level 30.
As for the gear, you need ton of time to have the money to paid them or you can do the quest in steel rake to have gold gear but its a repeat quest you have to accomplish 30 time and paying about 75k each time to have the item. We cant possibly have those item unless we stop working and concentrate ourselves to play this game during month to have excellent gear.
In the end, we suggest you do the daevanion quest, you will have a goldly armor and weapon(if you enchant to 10) for a long time. You will change your weapon for the xenophon,betoni quest level 43 and your armor,Aion Gold we suggest to find some piece of armor level at least 43 blue if you want better to the daevanion armor.
Unless you got a crafter that can do expert blue armor level 38, but crafting is such a pain in the ass in this game and boring, so, i dont do that.