Little bit of a late reply but since you hadn't mentioned whether or not you've picked a server yet, I figured I'd throw this into the mix in case it's what you're looking for.

We have a ton of headgears at
Anomaly Ragnarok Online, and we're adding more quite frequently (usually every couple weeks). We have a variety of shops for obtaining headgears, including plenty of quest headgears, as well as being able to get them through events, Zeny, and other methods.
The server itself isn't exactly designed to be easy (it's a bit of a blend of super high rate and low/mid rate elements), but everything is accessible to everyone, and with headgears all having the same effects you can pick whichever look you like best without worrying about getting the best effect. Most of the headgear quests take about an hour to complete.
You can take a look at our
Currency Guide for a list of ways to get headgears, which also includes a link to each method with previews of all the headgears. Since you mentioned quests specifically, those can be found
here.
And just to cover some of the basic server info, we're a super high rate (20k exp rates) with max level 500/200, and fully customize drop rates. We're planning to put a pretty big focus on PvM content in future updates, so there'll be plenty of quests available along with other content. We also have a number of client mods (such as integrated SimpleROHook), fully customized achievements/titles system, and since you like headgears, you may also be interested in our custom hair palette pack which consists of 181 hair colours and a separate option to change the colour of your hair accessories (hairties, ribbons, etc) if your hairstyle has any!
If you have any questions about the server before trying it out, feel free to contact me on our forums and I'll be happy to help you out!