Just from my own experience, Sycamore...........
Hand held saws (circular/jigsaw) can be quite unwieldy for accurate cutting if you're not terrible experienced. Also potentially dangerous.
I only use a jigsaw for fancy shapes etc, although a lot of tradesmen use one instead of a circular saw. I use a circular mainly for cutting large boards on a bench or supports.
I do as much as I can with hand saws, also I use a table saw all the time. This is a cheap one, but a good make..........
http://www.screwfix.com/p/scheppach-hs80-210mm-table-saw-240v/44937
Ideal for "running down" a piece of timber from, say, 150mm to 50mm or whatever. Set up the guide fence and poke it down through the blade with the pushstick. Set the timber at right-angles for cross-cut..... or at an angle for angled cuts. You can usually tilt the table to 45 degrees for mitres etc.
For kitchen fitting/skirtings/architraves, most people use a chop saw that can handle mitres and bevels. I don't know how much of that you plan to do.
For general work, I set up a simple bench on site, with a steel vice clamped to it. The table saw sits on the bench. With that and ordinary panel saws, I can do most things.