There are two projects that need accurate cuts:

1. I need to cut the ends off a 25” deep kitchen countertop, 1.5” thick, 1/8” butcher block wood over particle board. They call it ”engineered wood”. It is not laminate. It is finished on top and edges. The cuts will be done before installation is started. There are adhesive veneer strips to cover the cut edges.
2. I need to cut the ends off of decking boards in a straight line, 16+ feet long, after those boards are screwed into the joists. The boards are full 2x6 pressure treated pine, 1.5” thick. So, 32+ board ends in a row need to be cut in a straight line.

I need to buy a corded circular saw anyway. I saw these 100” tracks for an inexpensive 6” circular saw at the links below. Would these work? Is there a better option?

https://www.homedepot.com/p/WEN-100-in-Track-Saw-Track-Guide-Rail-and-Adapters-CT9502/312015100

https://www.homedepot.com/p/WEN-10-Amp-6-5-in-Plunge-Cut-Sidewinder-Circular-Track-Saw-CT1065/310735605

I don’t want to spend $500 on tools for basically 3 cuts. Less than $200 is better. I feel like I could use both the track and circular saw for other purposes. My battery operated circular saw stopped operating during some of the cuts of the old deck boards, which may have absorbed some moisture. I tossed my last corded circular saw before I moved because it was old, I didn’t use it, and I was a little afraid of circular saws. I’m better now - I use all kinds of other power saws.

I have not researched these tools in detail yet - just wanted to get some guidance on how to proceed. The countertop is a temporary reno which will be replaced in 3-6 years, so there is no budget for pros. I have built a composite deck before and tried to match the board lengths. It worked OK for that, but that method will probably not work for this new thick wood decking. I need to learn how to do straight cuts with a circular saw anyway.

Here is the countertop:

https://www.homedepot.com/p/Hampton-Bay-8-ft-L-x-25-in-D-Finished-Engineered-Birch-Butcher-Block-Countertop-PWBRAB386352490/318686095

Thanks for relevant tips!

Looks like Harbor Freight might have some options - I have not looked into these yet:

https://www.harborfreight.com/search?q=track%20saw