i'd like to get a sony ericsson k800i in brown, preferably with o2, i cant

Ya sure you can purchase the sony ericsson K800i mobile from some other network provider then unlock it freely use it with your o2 sim ...You can easily unlock the phone using sites like Unlock-Zone.com here they are rendering network unlock code for all mobile models at reliable cost .You first verify that whether the code is available for your country and network provider .If yes then pay for it and unlock your phone then freely use it with any GSM sim ...