Mick,
You are correct, ripping smaller stuff is not easy with a circ saw mainly because you cant support the saw on the work easily. If I was faced with cutting lots of this dimension of material I would prefer to do it on a bandsaw. If the "easyway" is £160 you could get a small hobby bandsaw for similar money (less for second hand?). Realistically, ripping is the only operation which is not practical with handtools. X-cutting can often easily be done with handsaw. If you bought one of these small machines, chances are you'll be able to sell it later if you grow out of it. The easyway will end up in the tip as you'll not find many buyers!
If you already have a circular saw (?) maybe you can adapt it by drilling through the base plate to accept a twin locking fence which will allow you to follow an edge very accurately. To provide sufficient support simply lay a similar sized board next to the one you are cutting so the saw can run along it whilst you cut the other. Do you have a large workbench to lay stuff out on?
I made my own saw table by VERY firmly screwing an old B&Q saw to the base of a thick piece of ply / chipboard. I routed a slot to take a fence which I locked in place with clamps once adjusted, and hey presto, a saw table. This top replaced the orignial (wolfcraft?) top when it was bent after falling down some of the stairs I mentioned earlier. In fact the fence was a good deal better than the orignal and would easily cut to 0.5mm ish.
We should mention crown guards and no volt release switches. You'll need to add something like these to any saw table you make. Hence I would prefer the bandsaw as it is much safer.
Cheers