I'VE JUST COME ACROSS THIS...
The first thing to realise is that for the best in planetary viewing you need very different things to eyepieces used for DSOs (deep space objects), which is where the emphasis is placed on most general purpose eyepieces.
The primary difference is that eyepieces for DSOs are optimised for wide field viewing. To do this they tend to use large numbers of lenses in several groupings which inevitably introduces lateral colour, which is the death knell to seeing fine low-contrast details on the planets. The extra air-glass and glass-glass transitions also introduce more light scattering which causes a halo effect around bright objects. Again, this is not a problem for faint DSOs but a major issue for planetary viewing. The Nagler designs are often presented in a rather lazy manner as being the best eyepiece regardless of the question asked. In reality they perform particularly poorly in planetary use, in large part because of the sheer complexity and number of elements.
True planetary eyepieces are different beasts altogether. The primary job is viewing bright objects with as much detail and contrast as is possible. All other considerations are secondary. There is a strong advantage to minimising the number of elements even if this also reduces the field of view. True planetary eyepeices give much better light transmission, infinitely higher contrast and the absolute minimum scattered light. Space is black with a planetary eyepiece. It is often a murky grey with a wide field design.
For specifics, the Orthoscopic recommended by Andrew S would not be a bad choice but for my money I would go for a TMB Planetary II, which is around the same price but it has the edge even if it is fairly marginal. 5mm is probably about the right focal length. In a perfect world I would have said one of the TMB monocentrics, which really are no compromise planetary eyepeices, with absolutely unrivalled nothing-else-even-comes-close contrast. However, those are out of production now and as a highly specialised eyepiece they are unlikely to reappear on the market for the foreseeable future.
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Question: Will I get a better quality with the Pentax 60 fov, than the 68 fov. Also, the Pentax has 7 elements. Isn't that a lot? This guy is saying here the more fov, and more elements, the less quality. Waveytone in fact said the same thing regarding number of elements. I was hoping the Pentax would be different. 
I also have a dob, and that's going to be tricky with 60fov. I'm guessing I need to make a choice between being practical and quality.Oh golly, golly just when i thought I was making a decision.
Sorry guys for dragging this thread out for so long...It's just I don't ever intend to spend up like this ever again on an eyepiece. I'm trying to be the best informed before I buy.. thankyou for you help and patience.