I assume the "best one" is the one gives the lowest quote, and I don't think there will be any differences in terms of "data quality" (Illumina sequencer dominates the DNA/RNA sequencing market). Just shop around, asking if the price is for sequencing only or includes some sorts of primary/secondary analyses.
I have used both Azenta and Novogene and had good results with both. I would contact each and ask to set up a meeting so you can select the company that can best fulfill your needs.