Buying simple java combobox for my tribot script

I've watched a few videos but I can't seem to figure it out. I need to implement a simple combobox (or whatever else will do the job) into my waterfall quest script. Basically user should be able to choose from a list of many options (probably 40-60) as to where they are in the quest so the quest starts at that point. All I need is some kind of skeleton, I will fill in whatever I need. I just need help implementing it.

Will pay $10 to whoever helps me. Add my skype please: KMJTgold