well Tod if all I was doing is cutting down sheet goods, about any saw will do.
However, acurate lines, the money is best spent on a worm drive circle saw. Heavier than the rest, but more acurate with less vibration, oh and a ton of power to boot. Milwaukee would be my choice.
Personally, I would stay away from cordless saws for the long haul. Batteries die faster than I want them to along with longevity of the battery is a concern and you end up chucking the saw once the batter no longer holds the charge since the replacement battery is almost the cost of a new saw. Yes they are great, handy, can cut curves very easily, light, blah blah blah, but I guess it depends on how you plan to use it. they never seem to have the power I want them to have. They are handy little buggers, but....
now, you mention drill/driver set. I can only speak of those in extremely positive manor, I absolutely LOVE my milw. lith ion impact and drill set. Was on sale for 211 with case here and I snapped it up. I have now used that impact in particular to put up 2 duck blinds, (1/4 lags 4" long with no pre drilling) 4 awnings with 1/2 lags, 2 decks, one was 20 x 20, simply love that thing. Now if you buy the set of them and the saw is there for the throw in, well then you are set. Oh, and the weight of the impact over the drill is amazing. Have I said how much I love that thing?