As a single-driver speaker user, I can tell you that this is a very careful path to walk, if you want to really get what they are capable of. The entire system needs to be of a caliber that will work best with these types of speakers.
Basically, you need a low power SET amp of high quality to drive the single-drivers. The reasons are complex, but basically that's what works best. Most single-driver speakers are very efficient(especially any horns), and they are very detailed and revealing. This means that the whole system needs to be almost free of any noise or any synergy problems. High power amps are not needed, because the speakers will play loud with only a few watts. Go for the purity and coherence of a good quality SET amp with that kind of speaker(which accentuates the purity and coherence itself, and is one of the main reasons for single-drivers).
Personally, I experimented with the smaller Fostex drivers like are used in the Hornshoppes, and found that they lacked the surface area needed to get reasonable SPL in my room. I eventually found my needs were filled by Lowther 8" single drivers. They play quite loud on a few watts, and sounded much better than the Fostex to me.
With single-drivers, the pathway is very narrow, if you want to get the best from them. But, the rewards are very good, for the strengths that come from a system like this.
Beware, that very low bass is not a strong point of systems like this. But, the sound that you do get, from about 40-60Hz(depending on speaker) and up, is very very nice.
My advice is to use a larger driver of around 8" diameter, instead of the small drivers in the Hornshoppe. Also, using rear-loaded horn enclosures(like Hornshoppe style),or Voigt Pipe, and avoiding front-loaded horn designs, will keep the sound from being too colored and "in your face" like some front horn designs can be. Real high-end front horns can be very good, but in the budget range, I'd avoid them.
Try to avoid solid-state amplification when using speakers like this. The advantages of SS are not useful with this type of speaker, and the disadvantages are clearly heard.