64gb is MORE THAN ENOUGH for any bare Os and word + browser. Once you install those make sure you change the Default save file to the D drive (500gb+hdd is recommended). Make a folder called "media" then inside it pictures, videos (movies and series inside this), music. Put the browser and word on his start menu/taskbar. Make another folder in D called Programs. Show your dad how to change save destination and you're set with the SSD and the OS.
I wouldn't recommend 4gb of ram. 6gb minimum, but since you're running dual channel I'd go with 8gb. RAM IS CHEAP, and the performance from not having enough ram (4-5gb is maxed out easily with normal everyday stuff like browsing, a word/excel document on and a video in the background etc.). Press control+shift+escape now if you're on windows 7. You'll probably be using 3gb ram now with your browser open. Now open facebook, a 720/1080p youtube video and OCN. That's 3.4gb for me. Getting 8gb will be fine for pretty much as long as you want to keep the PC (even 6-8 years LOL).
I don't recommend the stock cooler, it can get VERY noisy even if running a quad core cpu (95w MAX) on a decent load, plus keeping it cooler (instead of 60-80 degrees more like 40-50 degrees) would increase lifespan. Go with a low profile QUIET cooler like this: http://www.amazon.com/Thermaltake-Profile-Height-Cooler-CLP0534/dp/B003WOL4UG/ref=sr_1_2?ie=UTF8&qid=1333981752&sr=8-2
For the SSD 64gb is more than enough for the OS, office and a browser (with some room to spare).
Get a 500gb hard drive at 7200 rpm or more capacity if needed (Y).
For the CPU go with any locked quadcore, or dualcore. If you plan to keep this system for more than 3 years with NO noticeable slowdowns/lag I'd go with a quadcore. (Using my old dual core 640m (LAPTOP MOBILE PROCESSOR WHICH IS EQUIVALENT TO THE mobile processors at the time) which is 2.5 years old I notice some lag on video playback (discrete GPU so not integrated problem) and when on chrome it will freeze for a second or two with high cpu usage). This generation of i3's is obviously better but for longevity and smoothness of use a quad core would be nice. I'd recommend the 2500 (http://www.amazon.com/Intel-i5-2500-Socket-LGA1155-Processor/dp/B004EBUXI0/ref=sr_1_6?s=electronics&ie=UTF8&qid=1333981912&sr=1-6
) which is only $5 more than the 2400 (your original CPU).
Show your dad some cases, if it isn't a surprise, and ask him which he likes the look of most. Cooling isn't a huge issue as the CPU is the only output of heat which needs to be actively cooled and with no hyper-threading and no ocing the 100% load TDP is more like 70-75 watts which isn't much for your CPU cooler.