I would highly recoomene BUYING your manga; Good series wont come out in the states unless there seems to be a market for them. With most series made after 1995 being picked up by VIZ, Tokyopop, Darkhorse, et al. there is bound to be something that interests you comming out every month.
For Manga Sources, I usually just check out
http://www.animenfo.com and see how the anime is, then look on ANN to see if the manga is comming out soon. Right Stuf's website is awesome for manga reviews and release dates, plus they often have GREAT sales. Off the top of my head here are some good titles i've read lately that you might like:
XXXHolic is good and ties in with Tsubasa and Negima
Saikoano
Now (Korean Manwha)
Hana Kimi
Girl got Game
Boys Be
Gravitation
Clover
I.N.V.U.
Peach Girl
Snow Drop
Actually.. almost 99% of the CLAMP titles should be right up your alley.
My girlfriend is the manga nut, im the anime collector.. Together we have been know to keep several storeshelves bare.
