Looking at the eyepieces in your signature Liz I don't think you need to buy any more - maybe even thin the herd a little
.
A paracorr would noticably improve the edge performance of your eyepieces, if the edge of field is bothering you.
Here's some info about eyepieces you might enjoy reading:
http://www.astrosurf.com/luxorion/re...ons.htm#barrel size