Help getting to 2000 points

Hello fellow Lords and Ladies. I need some help and advice on how to expand my current household to 2000 points.

Currently sworn to my banner are: - Cerastus Knight Lancer - Knight Questoris (fully magnetised) - 4x Armigers (fully magnetised)

Available to answer the call is a unit of Adeptus Arbites (yet to be assembled), otherwise I am prepared to drain my coffers to muster a glorious host!

Some considerations:

  1. I am looking to get the army finalised including fully painted by the start of May for an organised event.

  2. I have a weakness for the Cerastus chassis; it looks fantastic and is such a pleasure to pose!

  3. I will be including LEDs into all Knights.

  4. My meta isn't super sweaty, but there are a couple of high pressure melee armies I worry about.

  5. I have never played with my Knights.

  6. I want my list to be fun to play with and against.

Hoping I can draw upon your collective wisdom! I will be finishing painting my existing Knights this week and plan to go shopping on Friday! What should I buy?