Hi Goen,
1)
Band select is a no go on Voice deployments, why:
If you are carying voice call on 2.4Ghz there will be voice gaps when roaming because the APs will stop responding to probe requests on 2.4Ghz pushing the phone to go to 5Ghz.
Although interband roaming is supported on 7925 as of 1.3.4 you do not want to use the feature wihtout making sure that 5ghz is indeed ready to carry voice in your deployment for the 7925 phones.
http://www.cisco.com/en/US/docs/wireless/controller/release/notes/crn6_0_188.html#wp598890
2)
Client link is not recommended neither, instead of beamforming and opeating on low data rates, you need to have 11 Mbps as the lowed enabled data rate for 7925 and ensure you have enough coverage with .67 as the cell border before roaming.
Align you wlc config inline with the 7925 deployment guide - http://www.cisco.com/en/US/docs/voice_ip_comm/cuipph/7925g/7_0/english/deployment/guide/7925dply.pdf
cheers
Serge