Hey Sunshine! I have seen your horses and one thing I would say is that they are not the average horse for sale at the moment. I have no idea what your price range is (and you don't need to share that with me) but I suspect that it is over the $5000 mark. So you want to be sure that you get your ads out to the appropriate market.
Websites like Craigslist and Equine Now are great for horses up to around that mark, don't get me wrong I'm not being snobby, I have used both those sites to sell horses. However, most people looking for horses over that $5000 range probably don't use those websites as much
. Not a be all and end all I am sure there are exceptions so don't everyone jump down my throat.
Dreamhorse is a good one and has a variety of horses but the one that I thought of for you is actually this one: Warmbloods For Sale
Check it out, see what you think.