Hello Helenio,
I may be wrong but I think that all necessary firmware/SW upgrade for linecards is made by supervisor after IOS upgrade.
We moved some mounths ago several C6500 devices in a campus from 12.2.(18)SXF to 12.2(33)SXH2 but we didn't upgrade any rommon in linecards before the IOS upgrade.
The IOS upgrade was needed to manage correctly the 8 10GE linecard
dir /all
Directory of disk0:/
1 -rw- 82524740 Jan 8 2007 17:04:12 +01:00 s72033-adventerprisek9_wan-mz.122-18.SXF7.bin
2 -rw- 28896 Jan 30 2008 06:05:20 +01:00 RT-RM-SXR000-B-E-2
3 -rw- 78212100 May 8 2008 19:40:36 +02:00 s72033-advipservicesk9_wan-mz.122-33.SXH2.bin
an we have the WS-6724-SFP linecard also:
sh module
Mod Ports Card Type Model Serial No.
--- ----- -------------------------------------- ------------------ -----------
>> 1 24 CEF720 24 port 1000mb SFP WS-X6724-SFP SAL10414U5N
2 48 SFM-capable 48 port 10/100/1000mb RJ45 WS-X6548-GE-45AF SAL10425GAX
3 8 CEF720 8 port 10GE with DFC WS-X6708-10GE SAL11413LUW
5 2 Supervisor Engine 720 (Active) WS-SUP720-3B SAL10403LHL
I think you can go straight to IOS upgrade
Hope to help
Giuseppe