Building a cavalry army

Good evening all.

With 11th coming myself and my brother are building new/updating old armies. I’ve been a Guard player since 2nd edition so have chosen to update Astra Militarum (alongside an Iron Warrior army too - Im a hobby butterfly and have sworn to stick to these two only)

Now I intend to start as a cavalry force. I have Dreir, 5 Death Riders and 5 Rough Riders and am in the middle of building and painting these as a beginning force. We will play 500 points and build up to 2000 probably in 500 point increment (maybe 250) as we build, learn and play.

Assuming Detachments remain as they are or very similar which do fellow players believe would best reflect this? I intend cavalry probably backed up by Sentinels for heavy support. I like the idea of it being a light/recon force. Is there a “best in slot” detachment for this? To be honest I’ll probably play all (don’t yet have codex though) as a learning process but wanted to ask a collectives thoughts.

I appreciate you all