To get the SME installer to ask for a driver disk during installation, you type in
accept dd
where you'd normally just type accept.
However, if the drivers did not come on SME's own driver disk, I won't hold my breath about using the RH 7.1 drivers you found. The kernel used in SME 5.1.2 is 2.2.19 (which is NOT the normal kernel found in RH 7.0 or RH 7.1) as drivers are usually tied to the kernel version the're compiled for.
However, that said, no harm trying.
Kelvin