If you get a new saw, yes, go for a handheld circular saw. The cheap
ones are perfectly usable, but they wont give as clean a cut as a good
one will.

IME the quality of cut is the same on all circular saws. I've used the
best and am currently using the worst :-) What is different is the ease
with which you can adjust depth/angle, and the general ergonomics. Not
important for occasional use.