I think that is the core issue. If you are coming at the science from a non-YEC perspective, it's just science. The "biblical" part usually implies creation science.
Christian Schools International texts are explicitly Christian texts recommended by Reasons to Believe as old earth friendly. I don't know if they are anti-evolution though
We used Sonlight K-3 and it was fine. I skipped a couple books and a DVD, but almost all of it was secular Usborne, DK, National Geographic, etc books with a daily schedule and worksheets and an experiment kit. The instructor guides have suggestions about how to introduce Christian themes along with the secular content if you so desire. It felt a little hodge-podgy compared to using a text on a single subject, but it was all laid out for you.