The short focal length eyepieces I have used have very little eye relief which makes them uncomfortable to use. For high power, I would stay away from the kellner design (Explorer II) because they have a very short eye relief compared to a plossl. A few people don`t like the plossl design, but most of us seem to use them and like them just fine. It is a well corrected design which is relatively easy and inexpensive to make well. Orthoscopic eyepieces also have good eye relief and are good eyepieces when well made, but they are a little harder to make as well as a plossl. This makes them a bit more expensive to make well.

I have a 10.5mm Tele Vue plossl which is a great eyepiece, but I don`t want to use anything with less eye relief than this. Maybe you should think about getting a barlow to give you the higher power. That way you could use a 12mm eyepiece with a 2x barlow and get the same power that a 6mm eyepiece would give you, and it would be easier to use.

Tele Vue and Meade have good reputations for quality at a fair price - and they have earned them with good plossl eyepieces. Other designs are a lot of money for most of us, perhaps one day I`ll have some Naglers ...

I have heard some good reviews about GTO plossls which are about half the cost of the more expensive plossls. They are probably a lot like the inexpensive Celeston or Meade plossls.

Good luck, Steve