You will also need a good jig, like the Kreg one, to bore a proper hole for the hinge cups (assuming you're using concealed hinges).
TO ME, a jobsite saw can be plenty accurate, depending on how good/what brand it is - you're building wood cabinets, not a nuclear reactor. The key thing to make sure of is that you adjust your saw to insure it cuts SQUARE. Where the jobsite saw might fall short is it may not have the necessary capacity for all the panel widths necessary depending on your design.
That being said, if you are getting a track saw, that can compensate for the lack of cutting capacity; however, one thing that can be fairly important in your cuts is REPEATABILITY AND SQUARENESS (if needed) between cuts which you have to be more careful of when using the track saw. If possible, you may want to gang cut similar panels to make sure they are exactly the same size when using the track saw.
When I built our cabs, I used a jointer/planer because I used rough wood. It's not necessary if you're using S4S wood - you just have to make sure you pick out the straightest ones you can. You will also have to be careful of any variation in thickness that can sometimes happen with S4S wood. Using S4S would save you a LOT of time over jointing/planing though. You can probably save a little money by using S3S and trimming off - but it will take more planning on what pieces you buy..
Remember to watch the GRAIN of the wood too (not a concern with ply), as you don't want to make the rails and stiles with wood that has a bad grain such that it ends up warping or cupping down the road, causing your doors to warp - try to find quarter sawn if possible. Though using the ply for the panels of the doors (since you're doing Shaker) can help stabilize from warp, but it won't help if you use stile/rail pieces that end up cupping. That's one advantage to jointing/planing rough wood though - you can pick pieces with not so great grain (as long as it's not too bad), let it acclimate, then joint and plane the warp out
You COULD get by without a router for Shaker doors, but a router with table would make it a LOT easier.
Random orbit sander because it's a b*tch to do so much sanding by hand.
I recommend this book - it has a lot of good tips, recommendations, and instructions:
Rather than repost pics, I posted a couple of pics of our incomplete cabs here:
A mechanic you trust is gold. That being said, I'm sure they have enough work without your oil change/brake job to keep their pockets lined. My PERSONAL philosophy is "if I can do it myself, I'm not going to pay someone else to do it." Although some tools might be too specialized to do other...
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