what i want is something kind of like the backpack mod, you right click holding an item and it brings up an inventory for that item, i also want to limit the inventory to just seeds, with the size of a small chest. if someone can at least show the basic code with place holders for vaiables that would be great.

you'll find *everything* you need in net.minecraft.inventory.ContainerChest ...

 

(this would also be your sample code with place holders you'll have to exchange for your own settings ...)

But is that able to be turned into an item instead of a block?

Simply make your item backpack open the backpack chest gui using onItemRightClick method.

 

I've not looked into how chest work so I couldn't help you but thats what i would do if i was making a backpack

But is that able to be turned into an item instead of a block?

 

behind the gui is the container with the player inventory and your special inventory (chest, backpack, saddlebags, whatever). The container doesn't know if it's been opened by an item or a block (or even a mob). The item/block/mob has to open the container GUI when triggered (right-click, shift-click, whatever). The GUI will load the container, the container will load the inventories and the inventories will load and store the contained items by means of the readFromNBT and writeToNBT methods ...

ive looked at it, and it still makes no sence i also looked at the forge tutorial and that made no sence. part of my confusion with it comes from the "func" methods as they do not give a clue as to what they do.