Unless you store films and vast amounts of data 32 gb will be more than good enough. You can use it to transfer files. Then wipe it and use it again and again to transfer more.
You say you need MS Office .. I bet you dont. MS Office is a huge programme that is capable of doing much more than most users will ever need. If you only write to friends etc. With Windows Operating Systems just scroll down and look in .. 'Accessories' and you will find Word Pad. This is a scaled down version of MS Word. Have yet to find anything it doesn't do for everyday use.
Have a look at it, you already have it on your system.
Your new system will come with Win 10 already installed emmie, so no need to worry about upgrading.
But for anyone who is still on Win 7 or 8.1 and hasn't yet moved onto Win 10 .. I can assure you that you can still upgrade for free, using the Windows Media Creation tool, readily available from Microsoft themselves.