I need to upgrade my ipad to the latest IOS but need some advice on what I need and what impact any upgrade will have on my apps, the baseband etc. Current setup is as follows:

Jailbroken (no idea what software was used to do this)
IOS 4.2.1
Baseband 07.10.00
Carrier Vodafone (unsure if unlocked)

After the upgrade is complete, the following is essential:

Must be able to use a vodafone SIM
Must be jailbroken untethered

Can someone please advise if an upgrade is possible whereby I can acheive the above?

Many thanks in advance