Array, Hashtable Or Binary Tree?

I am looking for the best performing solution for modifying and
iterating an object graph in JavaScript. I have outlined below a
simplified example of the object model and examples of how I will be
using this graph.

Object model:

Two objects, [BadApples] and [GoodApples] each contains a collection of
[Apple] items (500 max). [Apple] simply has an ID and a name.

Requirements:

A quick way of determining whether a certain apple exists in either
[GoodApples] or [BadApples] (by ID).

A quick way of iterating through [GoodApples] and [BadApples] in order
to update the web page.

A way of moving a certain [Apple] (by ID) between [GoodApples] and
[BadApples].

I currently have this implemented using arrays, but iterating these
arrays is expensive. Is there an implementation of a binary-tree for
JavaScript? The real-world application may contain many hundreds of
nodes, and performance is crucial.