Help with making a good logic model for a multiblock

[Pennyw95]

I'm trying to make a shelve (old and bad pic here ->

)

This shelve has 4 slots that will store items, much like the Bibliocraft version does, with the exception that it will have special

models for certain items.

 

Also, I'd like some items, primarily Thaumcraft's wands and staves, to take more than 1 slot: a wand would occupy horizontally

2 slots, and a stave would take 4 of them.

That means it would take the slots of another shelve adiacent to it, if present.

So, it would then become a multiblock.

 

What would be an efficient way to make this work? At first I thought of just having 4 booleans per TE, or

maybe something like each slot being a subclass of the abstract class Slot, extended by Free, Taken, Shared.

 

It might be too inefficient, but using just booleans could make reasoning about shared slots hard...

How would do it?