Magic amplification isnt the best as it only adds a random value to your maximum damage instead of full value like magic attack. So I prefer magic attack.
For end game I use 3 pieces of roxona and leather gloves to be able to hit 100% with carve for filler attack. carve attack is only bad at ET.
About weapon, I would use superior corona rod at lvl220 (or that one lvl220 blue rod I forgot the name of) instead of catacombs club. Catacombs club is a nice weapon for supports due to the health it gives, but if you want to deal more dmg it is sup-bar. Valia should last you until lvl220.
The reasons being that cata club will always give the same amount of magic attack and there is no way of increasing it by upgrading the weapon as it only gives you more weapon attack. Now if you use a superior corona rod you will be able to enhance the magic attack with anvil upgrades + you will be able to use squire weapon buff to make it even higher temporarily.
Also the aoe attack ratio wont help you cause your skills have hit limited charges.
So just use valia or some cheap lvl170 hammer to get to 220. Rods arent as good until you have the druid skills cause you will most likely have to use AAs as fillers anyway.
As for offhand, use shield for tankiness and arde/karacha dagger for more damage.
Wizards bracelets are good. Petamion is great but Animus necklace is even better for damage dealing purposes. The -hp regen isnt bad cause we have heal and you wont regen in combat anyways.