If cordless tools are wanted, (keeping benches and planters in mind here)
The best cordless tool platform to save weight, and be easy to handle would be a 12v system. IF, and I said IF - a handheld circular saw is a needed OR desired tool, then there is REALLY only one system that fills that requirement well, and that would be the Milwaukee M12, 12v system. Their m12 platform is industry leading, and their brushless "fuel" options in this lineup are almost unchallenged in some respects. They offer a 12v "fuel" circular saw specifically designed to be be small, but large enough to still cut 2x material. So 2x4's, 2x6's, ect, and any size plywood would be easily handled by this saw. Not to mention the options of drills and other basic power tools you might be interested in.
The only downside to the Milwaukee m12 platform for you is if your hands are also small, might be the grips. They may be a little large, by in my opinion I'd think this is something you can still work with. Milwaukee, like Bosch too, uses a stick pack battery that gets inserted into the handle. The nature of this design leads to wide handles. I'd highly suggest taking a ride to Home Depot if that's possible, and holding one of the Milwaukee M12 tools. That will also give you an idea of what a 12v Bosch, Ridgid and some others would be like too.
If a cordless circular saw is not needed, then consider the 12v dewalt or even Makita system. The small comfortable grips is where they excel by using a slide pack design of battery over a stick pack. The handles are much more comfortable to hold. The lighting on the 12v Dewalt's tools is also superior. But no good circular saws to be found on any of these other brands. These brands are where I'd say to look if you just wanted a drill and impact driver..
Like I'd tell anyone else looking into buying a new cordless tool kit - think of what you need, and what you might want in the future. Go from there. Examine what's brands offer what tools, and narrow down the field. The reality today is that most any premium cordless tool system will make you happy and work well. However as I stated in the beginning, if a GOOD small circular saw is wanted - Milwaukee is where to look. You don't want a jig saw for normal cuts. The blades are too flexible and will always twist and walk slightly while cutting anything thick. You will never wind up with a clean even edge. Jigsaws are for cutting curved cuts mostly, not straight cuts like you may want. A jig saw, is LIKE a portable scroll saw. For straight cuts you need a saw with a rugged blade that's doesn't bend
The Milwaukee website is very easy to navigate.. here is their m12 fuel circular saw..
Another good video for you
The upside, or downside of a larger miter saw, is that you either need to set it up, and bring the wood to the saw, or carry it out, and bring the saw to the projects. They are still "big" saws, unless you gets something very small like a 7 1/4(?)" saw. Still, not very portable, and you cannot cut something that won't fit into the saw.. there is no "trimming" of any wood already nailed or screwed down. This is why portable circular saws are more versatile, and are widely used on job sites. Miter saws are generally used for precise finish work, like moldings and trim work. They cut very accurate angles too.. People CAN and DO use them to make benches and planters, but to get the full benefit of a miter saw, you'd also want a stand to go with it. Either a designated miter saw stand, or saw horses and a table top of some kind. Their cuts will be more fine, and more accurate if that's what's desired, but you can forget about cutting plywood with one of those. Only you will be the best judge of what suits your needs and wants - so listen to advice, but make your own decisions..
My personal feelings, are that a table saw is not for you - not for this.. the miter saw is good idea if you have a work shop or work area you can leave it set up without moving it around. The lightest, and most portable tools for "not furniture grade" work in my opinion would be a cordless circular saw like the m12 fuel I mentioned. You can bring it anywhere without a hassle, itll cut what you need, and with a guide like a speed square or just a steady hand it will give you very accurate cuts.. things like benches and planters do not need laser straight accuracy for things that will be outside in the weather anyway. Woods shrinks and swells with the weather, so there no need to treat them like you are making bedroom furniture or kitchen cabinets..
