Ken,
You are going to miss out on part of the Zen experience by using the circular saw and straight edge... You might want to use a hand rip saw and then plane the hand sawn edge straight and square and parallel to the other edge. It's certainly doable! Pick up a couple nice panel saws (e.g., taper ground and breasted crosscut saw, and taper ground rip saw) and go at it! It certainly will add to the entertainment and satisfaction factors... and to the enjoyment time!
I recently taught my 8 and 10 years old sons how to resaw boards with a hand rip saw and then hand plane the sawn surfaces flat and parallel to the other side. My 10 year old has made the comment "Wood is magic!" a number of times as I've taught them how to use hand saws, coping saws, block planes, bench planes, and various marking and layout tools to make things. I've even had them do handcut dovetails and their first attempts were very good. I've got them scribing sleepers to the concrete floor (above grade due to rock) in the family room so we can put down insulation and an oak strip floor. Their scribe work is so good I don't check it before cutting... the sleepers fit fine the first time!
What really got them fired up was spending a few hours with Roy Underhill. Prior to that they were of the opinion that you NEEDED all the big stationary tools like Norm. (In hind-sight maybe they should have met Roy before they met Norm??) I've got a good assortment of large stationary tools and good quality hand tools. I've purposely been using hand tools more lately (even on the renovation work I'm doing now) so that the boys see how tasks can be accomplished with hand tools. It keeps them engaged by letting them know that hand tools are NOT inferior tools, i.e., they understand that just because I don't let them use the 3 HP table saw and 8" jointer doesn't mean they cannot get to the same place with the hand rip saw and hand planes.
John