Have a look at column f at
http://www.televue.com/engine/TV3b_page.asp?id=214
This is the focal plane position; refer diagram for an explanation.
You can see that most are at 0.25" with the most in travel being -0.38" and the most outward travel being 1.16". I'm not sure how that compares to others on the market but I would think most eyepieces available would fit nicely within the range of a standard Newtonian focuser with say 1.5" of travel. Note you can measure your own relative positions but allow for the thickness of 2-1.25" adaptor when calculating/measuring your own set.
If you had say the two eyepieces at the extreme end then you would need a focuser with 1.6" of travel. I think the Skywatchers scopes are designed for photo and visual but the latter needs and extension. Many focusers have 1.5" of travel but this figure does vary amongst makes and models. Some makes allow you to change the length of your draw tube.
To answer your question; yes, get all Tele Vue and you won't have that problem.
