If you are talking months before upgrade.. go with the puffer... It'll learn you fast, and is quick/easy to rig, and they sell pretty easy as they made a bunch of them... The hobbie will teach you some, the puffer will teach you more. Generally speaking it probably will teach you quicker than the hobbie what will most directly translate into a larger monohull as you upgrade.
Also the puffer is lightweight, and will be easier to right if you dump it.