I would add age, stallion/gelding status and probably his name (to make it more personal). Video if possible.
Hacking alone and in group or not happy with one or the other? Availability of trails close to the stable?
My preference is to see prices in adds (regardless of what kind of add), but this is up to you how you want to handle the process.
The fact that you are offering weekends is in my opinion a big plus (might expand your catchment area since your location is indeed not the easiest, but very nice - relocated from the UK in 2011 and though I have not been to the exact place, have visited the area).
Technical points, but your job probably involves going away (rather than evolve into it) and I presume the horse has no vices (rather than had no vices, but recently developed them).