Hmmm, I don't think the proof of funds requirement is quite as strict once you're landing as it is when we're doing the application, so I assume 6 months of bank statements would suffice, especially since they're rarely checked. But just to be safe, if I'm lucky enough to get my application approved, I'm going to get revised versions of my proof of fund letters that I submitted with the application (because I have no manner of luck at all and, with my fortune, I will get the one Immigration Officer at the airport who actually checks AND wants proper proof of funds letters). Debit cards and checks are always a good idea for ACCESSING your funds, but as PROOF of funds, they won't be helpful...