Key factors, what size are you getting?
Below 75”, forget 8K, even at 75” borderline worth it. You won’t benefit at what I would consider reasonable viewing distances .
then next factor, 4K is only just being more widely adopted in TV, streaming and film formats, 8K is impressive but rarely used format currently but will probably become more available in the next few years. Unless you are really a video/techno junkie then I would say go 4K. For the TVs themselves, last year the Samsung 8K was similar in picture quality (outside of pure resolution) to the 4K. I haven’t seen an 8K of this year model yet so can’t say what it’s like.
EDIT: sorry just realised you wrote 800b not 900b, The 95b should have slightly superior FALD and picture handling to the 800b.