You should be fine with those pistons if you are planning for a lot of power, like less than 250. The item said they were good to 300hp, and that may be the case, but I wouldn't push it too close. Just take them with you to the shop with your block, and have the cylinders honed to the right spec. Since you have a couple of scratched cylinder walls, get .5 mm oversized pistons instead of the ones you listed, and get the block honed to spec. STD sized pistons are not going to work for you if the scratches are too deep.