HTPC+Downloadrig config

Hi
Planning to get my third PC (thinking of building myself for first time) for following purposes:

1> HTPC (HDMI to Panasonic 42E5D)
2> Media Server(using Media Monkey) to same TV through cross cable.1080i/p files(no real time conversion)
3> 12X7 download rig (JDownloader + Bittorent)
4> Openoffice.org
5> All browser.
6> Games (extrem low end)
7> Win 7.

I want my system should be future-proof for 3 years (if not 5). Should perform above tasks with same speed till then. No micro-ITX board and addon GPU. Silent system is also my preference.

Now I am thinking of following 2 options:

Option 1:

1>AMD 2.1 GHz FM1 uPGA A6 3500 Processor + MSI A75MA-G55 Motherb Combo Motherboard (SATA 6 Gb/s and USB3)

2>WD Caviar Green 2 TB Desktop Internal Hard Drive (WD20EARX)

3> 4 GB RAM (preferably low cost)

Option 2:

1> i5 2500k + z77 (as for my future proofing need but only proc+mobo sucking most of my budget, Still I can postpone the built for couple of month gathering all other components)

2>WD Caviar Green 2 TB Desktop Internal Hard Drive (WD20EARX)

3> 4 GB RAM (preferably low cost)

I am using Intels since 1999 and having a notion that AMDs are only great on specsheets but tons of +ve reviews and budget is encourageing me to keep AMD as opt1.

Please guys help me choose.

Thanks.