[Q] LG Thrive (P506) Rom Upgrade?

[Dmoneh]

What's to stop me from trying to update with a Canadian or Israeli ROM for my LG Thrive? Is there that much of a difference between the phones abroad? I was at an Orange Store in Israel trying to get a SIM Card for my phone, which ultimately, they wouldn't sell me due to their insistence that I have an Israeli Identity Card and Bank Account or pay a refundable ₪ 2239 (about $ 600) when I can bring in both. While in the store, I saw the Optimus One, which more or less is just an internationalized version of the Thrive(?) like the Phoenix, which is just a monthly contract version of the PAYG Thrive. Anyway, has anyone tried using a different rom? LG, as I'm sure others know, have been a bit too slow in giving us updates for the phone, which is why I am willing to just go my own route. Lastly, I have heard that I can't upgrade to 4.0 because of the Thrive's Lackluster internals, and if true, what's the latest version of Android I can update to?