Quick 'SD Flashing' question

[krnfrk6663]

I recently upgraded to the TP, and now I have my Mogul that I'm thinking about giving to my mom, which she's on Verizon. Two things I'm wondering are, if it's possible to actually flash verizon rom and radio on it and make it able to work for Verizon, also, the other question is, how big a memory card would you advise for this. ( I Have a two gig sitting off to the side, but I also have a 512mb)
Thanks for the help.

(No I don't know anything about flashing yet, but I'm soon to be looking into it, since I have a 'test subject' now.)

Also, to clarify, I am on Sprint.. That mogul is a Sprint version. **Edit**