Thanks for the guide.
I bought an Optiplex 9020 SFF (i7-4790 + 8 GB ram) for $160 on eBay. I also had a BCM94360CS2 + M.2 adapter sitting around from previous failed Hackintosh attempts. Found a $15 PCIe to M.2 adapter and a $7 USB header adapter and WiFi/BT works perfectly. No more terrible Bluetooth dongles.
Everything is working great. Can't wake from sleep with the keyboard or mouse (even after enabling Legacy ROMs), but I don't really care since I can just push the power button and it wakes normally. This may also be due to updating to 10.14.6. It was working before I did that.
Totally recommend this for anyone who has tried and failed with Hackintoshes before. If you don't mind having a larger computer, the MT option is way better for GPU options and has an internal USB header available, but I prefer the smaller form factor.
If you bought the same adapter I did (CRJ 9-Pin USB IDC Dupont Male Header to Single USB 2.0 Type A Male Cable), only the 5 pin side of the pins are connected, which was the wrong side for my PCIe card cable. I had to pull a pin from the adapter (across from the blank pin) and then install the PCIe usb cable offset (some pins will be exposed). A bit janky, but it hides in the case anyway. Just make sure you check both cables for proper pin connection.