Also on the motherboard part, can you please let me know what difference would B75, H67, H61, H77 would make? TIA
The differences are as follows --
The H67 and H61 chipsets are from the Sandy-Bridge era and fall under the Cougar-Point family of chipsets, they are fabricated on a ~32nm lithography process. The H- in the name denotes their usage as budget / mainstream class of motherboards that are meant to be used by users who are disinclined to over-clocking and whose main usage will focus around HD media, day-to-day applications and gaming.
The H77 is an updated chipset released along with Ivy-Bridge processors and falls under the Panther-Point chipset family. It is fabricated on a ~22nm lithography process and shares most of its features with its predecessor, the H67. Major differences are that the chipset now accepts RAM upto 1866MHz by default [no need to over-clock, feed more voltage] and the USB 3.0 controller is integrated into the chipset.
The B75 is Intel's latest fielding in the Business class motherboard series, it shares a lot in common with the H67 and H77 but adds certain business-centric technologies like VT-D and VTx into the mix [these must be supported by processor too].
So all in all this is how they stand --
H61 --> extreme budget motherboard for the Sandy-Bridger / Ivy-Bridge line of processors lacking current generation connectivity options like USB 3.0 and SATA III ports.
H67 / H77 --> mid-range class motherboards for the Sandy-Bridge / Ivy-Bridge line of processors mostly alike in features except those mentioned above. No support for over-clocking but full suite of connectors like USB 3.0 and SATA III.
B75 --> Panther-Points budget offering for Enterprise class solution, the B75 is geared to be at the heart of a business analysis machine OR corporate workstation and amalgamates a lot of functionality in itself.
GIGABYTE retails a motherboard that is undercutting other chipsets and offers full functionality, lacking over-clocking but supports all modern standards like USB 3.0 and SATA III.
Hope this answers your query, Cheerio!