Couple of options. Just going through this right now with my build. What I found is:
Speed Pro 2482 is the old-school TRW "flat top" forging with the four small valve reliefs that look like a HiPo.....I think they are 2.7cc volume total. These run the typical older 5/64 5/64 3/16" fat ring package, and 1.605" compression height. Generally speaking, that compression height and a 5.155" 289 rod puts the top of the piston close to zero deck, which will maintain compression near the original 10:1 intent. Note that a lot of replacement pistons called out for 289s these days run a 1.585" compression height, which will result in the piston down in the hole pretty far, and sap a lot of compression away. If that's important to you, and it sounds like it is, you have to keep an eye on that. Link to Summit for these pistons:
https://www.summitracing.com/parts/slp-l2482f30
The other option, which is what I am using, is a "Summit" branded 4032 forging with 3cc eyebrows. These are make by RaceTec out in California, which was the former owner of JE pistons, and are a very quality piece. They are 1.605 compression height, lighter than the old 2482s, and most importantly to me, run a modern 1.5 1.5 3.0mm ring package. I won't go into why I like that, but the difference is real. They are pricier, but I only plan on building my K engine once.....I hope! Here's a link to those:
https://www.summitracing.com/parts/SUM-SBF302030F
Hope that helps.
Kevin