PicoPSU advice?

Hi all. I'm about to start collecting parts for a HTPC/server build, and I'm thinking about using a picoPSU (very little case space and noise is an issue)

What sort of wattage pico would I need for this build? Would 120W cover it?

CPU: Intel Core i3-2100 3.1GHz Dual-Core Processor ($111.99 @ SuperBiiz)
CPU Cooler: Silverstone NT07-1156 40.0 CFM CPU Cooler ($19.99 @ NCIX US)
Motherboard: ASRock H67M-ITX Mini ITX LGA1155 Motherboard ($91.97 @ Newegg)
Memory: G.Skill Ripjaws Series 8GB (2 x 4GB) DDR3-1333 Memory ($42.99 @ Newegg)
Storage: Western Digital Caviar Green 2TB 3.5" 5400RPM Internal Hard Drive ($139.99 @ Adorama)
Storage: Western Digital Caviar Green 2TB 3.5" 5400RPM Internal Hard Drive ($139.99 @ Adorama)
Storage: OCZ Agility 3 60GB 2.5" Solid State Disk ($49.98 @ NCIX US)
Case: Thermaltake VL52021N2U Mini ITX Desktop Case w/200W Power Supply ($55.99 @ SuperBiiz)

Also I might be looking at doing some light (but modern) gaming, in which case the Radeon 7750 seems the best (single-slot) power/performance choice - but it can pull ~45W going full-tilt... Would 160W cover that? Or even a 120?

It's been a long time since I built a PC, so I'm struggling to work out the start-up load & the various rails.

Is there any real advantage with going for an i3-2120 over the 2100?

Thanks for any help.

Thanks a lot.

Do you think I'd be able to get away with an i5-3570k? Not overclocked, but the upgrade to HD4000 graphics seems pretty significant, and I would really like to play some games...