BC2.9 and BC3.2 refer to the thread size inside the nipples, which the spokes thread into. Those thread sizes are "heavier duty" ones in the bicycle world, used for cargo bicycles and trailers.
A
5.0mm spoke wrench will fit the front spoke nipples, a
5.8mm will fit the rear spoke nipples. Note that the nipples are tapered where you put a wrench on them so the correct size wrench won't slide all the way down the 4-sided nut face on the nipple, but should instead become tight on it part way down toward the rim. These are fairly unusual sizes, so if you buy a spoke wrench kit make sure it actually includes those sizes.
You shouldn't need a spoke nipple driver unless you're relacing your wheels, and even then you can get by with a flat blade screwdriver (which can even be ground down into a DIY nipple driver).
If you look at a parts diagram you'll find very little in common between the
front and
rear wheel assemblies other than the inner tubes and rim strips. Different tires, wheels, hubs, spokes, etc. The rear spokes and nipples are indeed beefier, just like how the OEM rear tire has a higher load index (50) than the OEM front tire (44). You may have also noticed that the OEM tires have their tread patterns in different directions, that's to match the different forces that each tire experiences - rear tire experiences more acceleration forces, front tire more braking forces.
IMO keep "if it ain't broke, don't fix it" in mind and don't fiddle with your spokes if you're not committed to understanding, taking your time, and having the equipment on hand, to properly true the wheel on a stand. It's one thing to tighten a very loose spoke for a limp-home fix, it's another to take a wheel that's fine and introduce a wobble by tightening up spokes that don't need much adjustment, if any, for thousands of miles, depending on your riding conditions.
If you are interested in that, may I recommend starting with bicycles? They can be (but aren't always) cheaper to work with and more forgiving (read: less likely to injure or kill you) if you make a mistake.
Some great resources are
Sheldon Brown's page on bicycle wheelbuilding and "
Professional Guide to Wheel Building" by Roger Musson. The latter is an eBook you can buy online that's also engineering porn, every formula you could need for determining spoke length for different
bicycle wheel and hub sizes as well as lacing patterns, a detailed explanation of the physics behind spoked wheels, and the answers to just about any question you could have while building or tensioning and truing a wheel. It is likely what the designated "wheel builder" at your local bike shop has on hand for reference when something unusual makes its way to their stand.