1-- think about buying a set of interchangable needles.
(there are several brands/styles, some are cheaper, some more expensive, some often discounted. (most can be resold on ebay/etc for 90% of original purchase price, so if you find you hate them, its not a total expensive loss!)this way you'll always have the size and length you need.
2--LONGER (WAY LONGER) needles can substitute for shorter needles!
a 40 inch or longer needle can be used in place of a 20 inch needle (sometimes more easily than a 24 inch one!)
the process is called magic loop. it often promoted for socks, (and it works well for socks) but it can be used for many other things as well
basicly, the excess cable (cord) portion of the needle is made into a loop
the stitches are divided in half (or there abouts) and when you work them, you have extra loops of cord at either side of the knitting.
when one end of the circular needle is 'pulled' to make it possible to knit the stitches in 'front' the result is 2 loops (of exess cord) at each side!)
these loops work best when they aren't too small, (which is why a 40 inch long needle works better (bigger easier to manage loops) than a 24 inch one (tight twisty loops!)
(i was unsuccessful posting a picture, i get one, and come back and edit)