Then I'd recommend something along these lines, assuming a similar budget to the DD. Build yourself, or pay an LGS or ADCO to assemble the following parts:
Upper - Barrel: Triarc Track 2.0
11.5in $250. You'll build as a pistol first, then possibly SBR. Or you can get a 14.5in Lothar Walther instead and pin an extended A2 if you really don't want to go through the process, but I'd recommend shorter for HD.
- Upper: Aero no FA $60 or FA included $70.
- Handguard: ALG EMR V2 or Aero Quantum 10in (12in if you go with the 14.5in barrel) your preference $100.
- Gas Block: Superlative Arms clamp on .750 (or SLR if the SAs are out of stock) $90.
- Bolt Carrier Group: LMT Enhanced $325.
- Gas Tube: Any carbine length (mid length if you go 14.5in barrel) SS $15.
- Charging Armageddon Tactical GMS-15 $80.
- Muzzle Device: Get a cheap A2 for now ($8). Grab a suppressor down the road, I'd recommend a Q Trash Panda or SiCo Omega with Area 419 QD mount and flat end cap as of now.
- Optic (not in budget): A Vortex, PA, Sig, or Holosun will probably be fine for HD as long as you check it. If you want bombproof I'd recommend the Aimpoint T2.
- Light: streamlight ProTac $95.
Lower - Lower Receiver: Aero, Anderson or PSA $40.
- Small Parts: Red Barn Armory or Sons of Liberty Gunworks (or PSA if you have to) LPK $35.
- Trigger: Hiperfire EDT $60, or if you want to bump up the budget the Hiperfire Eclipse $199 which is well worth it.
- Buffer Tube+Buffer Spring+Weight+Stock: BCM A5 kit ($99) + brace of your choice (SBs are nice) while you wait on SBR stamp, then add a Roger's Super Stock or MFT minimalist $35.
- Grip: BCM or similar grip $19 (personal preference part).
Accessories/Misc - Mags: ASC if you reload, Lancer for factory ammo.
- Lube: Slip 2000 EWL.
- Cleaning kit: Real Avid AR $35
- Sling: Frank Proctor WotG sling $19
Comes in right at $1400 for the rifle alone. Will massively outperform anything off the shelf close to the budget in every metric.
Let me know if you have any questions!