Hi Vespine and welcome
I agree with Steve. The 1.25" GS Plossl eps that you will get as standard with your Dob are of reasonable quality. The 30mm SV 2" ep likewise. Plossl eps are a great starting point for both planetary (in combination with a good barlow to boost focal length), and deep sky observing.
The problems associated with 'fast' reflectors - and I mean our F5 dobsonians - manifests itself when you try to get nice wide views. You tend to get little 'seagulls' where there should be pinpoints of light.
This occurs "off axis", meaning the centre 50-60% of your field of view is in focus, and the remainder - the 'edge' of the field of view - is out of focus. The is due mainly to a condition called coma, inherent in fast designs. I find this distracting and unpleasant. The only way around this is to purchase high quality eyepieces. Eg Teleview Panoptics and Naglers and the like.
No low-cost , wide angle eyepiece will be sharp to the edge. I stress again, this only becomes problematic when chasing nice wide views of those beautiful deep sky objects. After all, that's why I personally bought a 12" reflector in the first place.
There is a group of us about to purchase and evaluate a (new?) type of wide-angle eyepiece made especially for planetary viewing:
http://www.iceinspace.com.au/forum/s...ead.php?t=7400
You will find your standard plossl eps that come with your 'scope adequate for planetary work, but pretty soon you may be wishing for a greater apparent field of view. That is, you will have more time to allow the target to drift across the f.o.v. before you need to nudge your dob.
When you are talking "extreme range" of you dob, do you mean maximum magnification? This figure is around 2.4 x aperture in mm, or around 720x for a 300mm aperture.
But whether you can achieve this magnification in practice is totally dependant in the seeing conditions at the time. remember, more magnification can mean a larger image-scale (things look bigger), but at the cost of image sharpness, contrast and definition. High power eyepieces are for getting up close and personal with planets and Luna; and low power, wide angle eps are for most DSOs.
You will find that discolouration at the edge of the f.o.v. (chromatic aberration) is not such a problem with you reflector, than it is with cheaper refractors.
The above is meant as a guide to determiningg what
type of eyepieces to buy. Other, more experienced users may offer better advice on what specific brands to buy. I like your sign off line: spend plenty of time at the eyepiece and this will help you learn about what you'd like to have in the future. Also, get together with other astronomers and look through as many eyepieces as you can, before committing your hard-earned $$$.
Hope this answers some of your questions without causing too much confusion.
Cheers
Dave W