SQLSRV is the only driver for PHP that is capable of storing UTF-8 strings into two-byte columns (NVARCHAR instead of VARCHAR) which is cu
NVARCHAR
VARCHAR
I Googled a bit more after I read this and I may have found the answer. On Debian:
# apt-get install freetds-common freetds-bin unixodbc php5-mssql
That will install everything PHP needs for Free TDS and allows me to connect using the sqlsrv driver.