I don't know about CreateSpace, but I'd strongly advise against Lulu for self-publishing unless you plan to only put together a few books... it's not a matter of quality (their quality is outstanding, actually), but of price--they charge far too much for the final product as a result of absorbing setup fees into the per-book cost. (A friend of mine previously used Lulu for all her books, and just couldn't move them because the cost was much too high; her reprints through ComiXpress are much more affordable.)
I personally use
ComiXpress for my printing; I've also seen some nice-quality books through
Ka-Blam, which I haven't really used for anything but some flyers. I do know for a fact that ComiXpress will work with custom sizes, so you don't need to worry about size/dimensions with them, only that all your pages are the same size. (and if you use ComiXpress in the future you can put me down as a referrer to get a 10% discount on either your setup or first quantity order--I suggest the latter, since it usually costs more.)
If you want standard sizes, what I've got for pre-reduction sizes on my paper supply is:
Western comic: 9 x 13.75 safe zone (11 x 17 full page size; can't find a ruler for this board to measure the bleed zone)
Manga: 9.5" x 13" bleed area (full page size 10" x 14.25"
wink
Naturally, both get reduced when printed; Western to 6.625x10.25”, not sure on Manga but it should be on the same formula.
(Measurements are lifted from Canson "Fanboy" paper for the manga size, and Blue Line Pro boards for the western size.)