There are 3 main choices, Raymarine, B & G, and Garmin. Raymarine tends to be less expensive, B&G more fully featured. Keep an eye out for sales. Defender has a big sale in late March and the prices will be somewhat better, but still in the 4 figure range.
These systems all use NMEA 2000 which allows for easy system expansion. You may also be able to find some items from HummingBird or Lowrance, but these probably don't have wind data.
Standard Horizon has been out of the marine instrument business for a very long time, 15 years maybe. You may find suitable heads on eBay. Back in those days many of the devices were and the transducers used proprietary protocols thus mixing and matching between brands was not possible.