3GS IOS migration, BB downgrade, JB and desimlock...which order ?

[zorglub!]

Hi all
i'm currently using a 3GS IOS 4.2.1 with bb 06.15..( jailbroken and desimlocked, but loss of GPS due to Ipad BB..
i'd like to migrate this 3GS to 5.1.1 with untethered JB and desimlock.
I've seen that with new tools ( redsnow 0.9.14b1), I can dowgrade BB to 5.13.04
Question:
1) should I use redsnow on curennt config ( IOS 4.2.1, bb 06.15 ) to BB downgrade, and once back to bb5.13.04 then migrate to ios 5.1.1 and then unthered JB and desimlock
OR
2) should I migrate first to 5.1.1 ( this operation, if I get it right does not change the 06.15 bb...) , then run redsnow to downgrade the bb, and once that done, untethered JB and desimlock

Could some one clarify ?
thks and rgds in advance

[tehh4ck3r]

Migrate to 5.1.1 first and then downgrade your BB

[eleshkk]

first save ur shshblobs of ios 4.2.1 then do what u want