If it already has 3.55 OFW on it then why would you "need to put the original 3.55 on it"?
I may be misunderstanding what you said with that.
Just stick the new drive in and format it. It would be ready to receive the CFW of your choice.
My personal recommendation would be Kmeaw CFW and multiMAN.
I have no experience with bitsbubba's NFW (noob friendly ware) but have seen a lot of good things with it.
Another good backup manager is Rogero.
I haven't updated my Rogero in quite a while, but it is a good manager (and he has recently done some things that is making me want to update (I just haven't had the time to do it)).
Until something absolutely SPECTACULAR comes along and blows kmeaw and multiMAN out of the water..............I will stand behind it wholeheartedly.
If something were to come along that is better than multiMAN, I'm pretty sure that dean would bust his ass to get the better parts implemented into his manager.
BTW, congrats on the "new" PS3!
I would much rather go to my grave not needing my gun, than go there wishing I had it.