Confused about remote access, can you enlighten me

remote access-

HELP ` I'm a bookkeeper,  currently 4 clients and growing; I've been researching remote access, LogMeIn does not work unless client leaves their computer on after hours-some clients do not want to do this and do not want me to access their computer during working hours.

Sometimes I use a USB to download their files, make adjustments at my office/my pc (I currently use PRO 2009) and then reload updated files via USB drive back to their computer, however, some of my clients are not willing to  upgrade to 2009  or 2010.  Was told to get Premier Accountant version and this would not required them to upgrade once I make adjustments and reload from USB back onto their PC.  Is that correct?

I also wondered about the online version?

I would  greatly appreciate some feedback to shed some light please on any suggestions so I can operate whatever version a client has and not require them to update every year?  I think every 2 or 3 years would be reasonable but most clients outsource their payroll or 1009 and do not really need the updates.