There will ALWAYS be another horse. Also keep in mind that you haven't actually seen this horse in the flesh yet. Most sellers will try to really push the good points of the horse and leave out the bad. Until you see the horse personally, you cannot fall in love and come to the decision that this is the horse for you.
I guarantee, you'll say it every time you see a horse that you like, you'll think 'there'll never be another one' and 2 weeks later, you fall in love with another one!
The problem with first time horse buyers looking at horses without a coach with them, is that they fall in love with the first horse they see, they go in with rose coloured glasses on and don't look at the horse's flaws, ignoring that the horse is really not suitable for them.