I know there are quite a few you can have done but which would you say are the most important? I wanted Miley to be scanned for HV, my vet suggested waiting til she's about 9 months.
Would appreciate any helpful input.

I don't know but maybe someone in the breed will be along shortly, however, I would think the first thing to concentrate on is Miley's show career.  Little point in paying for health screening if he is not showing the quality that would justify his use in breeding nor are you likely to get any equiries beyond BYBs.  Once you are involved in showing, joined the Breed Club etc you will find it pretty easy to keep up to date with what is required or available at the given moment.