Nope, there are 2-stroke and 4-stroke jackshaft kits, this is a recent 7-speed 4-stroke shifter.
If you have the funds then a 4-stroke direct drive is the easiest to build and operate and we really like the HS 49cc HS with new 4G transfer case from gasbike.net for $350 here in the shop, they are pretty easy to build and a joy to ride.
For a 4-stroke you want a big bicycle center cavity and even though the 29" Macargi Fatal Love is just a coaster brake beach cruiser the 49cc's grunt power loves those 29" wheels and it will do 30+ MPH once you wind it up.
You can fit darn near fit anything them like this one a 79cc Predator 4-stroke and Q-matic transfer case.
You are looking about $600 for a 49cc 4-stroke Fatal like my example.
The Fatal Love makes a poor choice for 2-stroke however.
If you budget is smaller then I suggest you build a simple 2-stroke direct drive first, it takes the least amount of money, skill and special tools to accomplish and with that 7-speed hub you should be able to mount the rear sprocket easier than on a single speed beach cruiser, at least they are on a Pantera 7s, the sprocket pretty much aligns itself.
There are all kinds of options for building.
To asses what your needs are, the top 3 are mechanical skill/tools, stature/needs, and of course your budget.
For example if your tool box has nothing even close to new and your favorite tools are a crescent wrench and pliers factor in a set of new tools in metric and a challenge.
For stature and needs how far do you generally travel per trip 1 way, the terrain, and your inseam/weight as those help determine a bike you can ride and engine type.
Jot down all of those on paper first and that will give you a compass to figure out what would be best for you ;-}