Hi, kathavatthu and its commentary were translated and published by PTS as "Points of controversy" and "The debates commentary" :http://www.palitext.com/
From their Translations page:http://www.palitext.com/palitext/tran.htm
Points of Controversy, tr. S.Z. Aung and Mrs C.A.F. Rhys Davids, 1915, 1993 ISBN 002 9 £23.65
The Debates Commentary, tr. B.C. Law, 1940, 1989 ISBN 019 3 £20.60
Not sure if this is pricey, but once you buy their books, you generally end up using them for decades. And they are always a great gift/donation. Also, if you become a member of PTS, I think you get from them a free book of your choosing once a year.
Also, if you have a big library close by (and in particular a university library with a department for Asian studies or something like that) they might have a lot of PTS books that you can borrow. Mine for example has pretty much the entire canon and many of the commentary translations by PTS.
NOt sure if there's another English translations of kathavatthu, though I think Ven.Pannasikhara mentioned that there's a working translation by Conze, which is easier to follow than the PTS translation (which can be difficult since it's about a hundred years old).
Regarding dsg, this is the direct link to the current Useful posts file:http://groups.yahoo.com/group/dhammastu ... _Posts.htm
As Chris mentioned, you'd need to become a member of the group to access it.