It would help if I closely read the original post
While I don't know the Optex brand, I suspect that they are similar in quality to the existing eyepieces that you recieved with your scope...I'd encourage you to use the eyepieces that came with your scope for a while...and I would not rush out and to buy more of the same.
My general advice is to buy fewer better quality eyepieces instead of having a whole case full of low quality eyepieces...In any given night I do most of my viewing with only a couple of eyepieces...so I reasoned I'd get the best that I could for those 2 or 3 (at least to start with).
I'd shoot for as good a quality eyepiece as you can (read as much as you are willing to pay) that gives around a 2 mm exit pupil in your scope...with as wide a field of view as you can get (since your scope is undriven).
From the Televue website...
EXIT PUPIL
The exit pupil is the image of the objective that is formed by the eyepiece. It's where you place your eye to see the full field of view. You can calculate the diameter of the exit pupil by dividing the focal length of the eyepiece by your scope's focal ratio:
Exit pupil = eyepiece focal length ÷ telescope f/#
For reflector telescopes, it's best to avoid exit pupils larger than 7mm or smaller than 0.5mm. Refracting telescopes have no upper limits on exit pupil sizes.
This is similar advice to what koputai was suggesting...
There are a number of good articles on the Televue website in the eyepiece section about choosing eyepieces for small dobsonian reflectors...even if you do not choose any of the TV products, the advice is still valid...
Good Luck!