You don't have to think too far outside the box for your Prototype tech. There are always new 'Decks to steal, or cyber arms, legs, and other bits of stuff.
This isn't a new idea, nor does the prototype item have to be that "wild, crazy", and "better!".. A Prototype tech that shaves 1/1000th off the production costs of an item and does that exact same job is a huge win for a company! Especially if that item is something that they make a billion of a month. (Like the humble O ring. )
This type of thing happens every day today, well, every marketing cycle, Samsung, Apple, HTC, and every other company trots out their "brand new and improved" phone... and usually all you really get is a furniture change and a camera upgrade to the best camera tech of 2 years ago.. (So those idiot Selfie Junkies can take even more narcissistic pictures of themselves) But at the end of the day, it does everything last years model did where it counts (talking, texting, web access).
So, by having your runners go out and acquire a piece prototype tech, you may be introducing them to some cool piece of tech they didn't thing about, and may want to "acquire" a second copy for themselves... and you get to use the standard stats from the book. (they improved the elasticity of the muscle fibers, decreasing their maintenance wear by 5%...No that doesn't mean you get an extra stat point, or Capacity. But you don't have to go to the CyberDoc as often!)
This concept isn't new to SR either. Back in the tail ends of 3e, they put out a book called S.O.T.A 2063 (state of the art). In it they broke down that the "quality" of electronic gear constantly degraded as newer tech came along while not actually changing the positive stats of a device/item/deck. So, tech based characters had to constantly spend money making sure their programs, and hardware were the latest and greatest, or they would get a TN modifier... (Essentially, IMO, this new concept was designed as a "money bleed" for GMs to bleed away cash from players that were getting too rich, as the costs for keeping things up to date got hugely expensive!)