I've looked at the options as well. No matter where you get it you have two choices for horns... You have Nathan who makes the AirChime, That brand is on all the locomotives here in the US. Then there is Leslie, They can be found on ships, boats, Trolleys and metro rail cars. For the real deal train horn go with the Nathan K5LA, The K3LA is nice too but the K5LA is the shocker. There's a guy selling the K5LA's on Ebay for $725, They are restored and better than the new castings. Look at eBay item #260564961843. The Leslie horns are nice and loud but you won't get that freight train sound like a Nathan. Hornblasters kits seem to be expensive, Better off piecing together a system. You'll need to plumb a 1/2" to 3/4" line for a big horn setup... . 150+ PSI!