If that is only thing you will be doing is office related work then you found a decent for your needs card. Gaming and high ress video then you might want something that is just a little more powerful.
the ATI 4350 is more then capable to run DVD video and operate dual monitors. I have two 4350's doing that exact thing. Installing it is rather easy especially with Win7 since it installs drivers for you, once connected to the internet.
The HD4350 will be fine for what you are describing. An HD5450 has more current video/audio playback features and is also within your budget but unless you are planning to hook the computer up to a television/stereo I doubt they will mater to you.
Yup, memory in those cards are just marketing propaganda.
the 4350 would be great for you needs, though a 5450 will run cooler/decode slightly better, so It is worth the slight premium if you are a Temperature person.
I agree, almost every one likes a cooler running card.
I haven't looked it up but do you really think there's a noticeable difference in temps between the two cards? They both use almost no power.
i recall reading test on a passive/fan cooled 9400GT (i believe). Neither card ran cool but the difference between the two was small, around 5c. Most small card fans are better for decoration then actual cooling.