Which technology to choose for your cannabis genetics depends a great deal on what you're interested in learning.
The simple answer is that sequencing will find novel variants and the SNP array, or SNP chip, will not. This may seem like a subtle difference but there is a lot of novel diversity to be discovered in Cannabis.
If you are charting out a strain for the first time, you may want to go with sequencing. Medicinal Genomics offers the StrainSEEK® panel and whole genome sequencing services. We also have partnerships with other providers of sequencing capture panels that license our content.
If you are scanning over a cross, (a cannabis strain where the parents have already been sequenced) the SNP arrays are likely the more affordable path.