For office use all is good enough

If you want intel an i3 with 4gb of ram and a H87 mobo (asus, gigabyte or msi)
If you want amd go for a a10-7600 apu 4 gb ram with a fm2+ motherboard (this for example http://www.gigabyte.com/products/product-page.aspx?pid=4824#ov)
You can't go wrong
😉