how to buy an ideal laptop RAM module?

[vishnu vardhan <vishnuvardhan.linux@gmail.com>]

facts:
i have recently purchased a laptop. it is shipped with 2gb ram. the
maximum ram is 8gb.
i want to replace 2gb ram with 2 4gb ram modules.
i did ask once in chat about the ram, and a person has given me an
idea about what type of ram i should purchase.
the laptop manufacturer did not provided any cd or manual.
so far so good.
i want to buy only kingston [btw, you can also recommend or suggest to
a novice like me other than kingston].


reality:
there are no mdoules available in indian online shopping websites.
i have also contacted my laptop manufacturer through email & phone,
and they have no idea ??!!?

my memory modules details :
# dmidecode -t 16
# dmidecode 2.9
SMBIOS 2.7 present.

Handle 0x000D, DMI type 16, 23 bytes
Physical Memory Array
    Location: System Board Or Motherboard
    Use: System Memory
    Error Correction Type: None
    Maximum Capacity: 2 GB
    Error Information Handle: 0x0011
    Number Of Devices: 2


# dmidecode -t 17
# dmidecode 2.9
SMBIOS 2.7 present.

Handle 0x000E, DMI type 17, 34 bytes
Memory Device
    Array Handle: 0x000D
    Error Information Handle: Not Provided
    Total Width: Unknown
    Data Width: Unknown
    Size: No Module Installed
    Form Factor: <OUT OF SPEC>
    Set: None
    Locator: DIMM 0
    Bank Locator: CHANNEL A
    Type: Unknown
    Type Detail: Unknown
    Speed: Unknown
    Manufacturer: Empty
    Serial Number: Empty
    Asset Tag: Asset Tag:
    Part Number: Empty

Handle 0x000F, DMI type 17, 34 bytes
Memory Device
    Array Handle: 0x000D
    Error Information Handle: 0x0010
    Total Width: 64 bits
    Data Width: 64 bits
    Size: 2048 MB
    Form Factor: SODIMM
    Set: None
    Locator: DIMM 1
    Bank Locator: CHANNEL A
    Type: <OUT OF SPEC>
    Type Detail: Synchronous
    Speed: 1600 MHz (0.6 ns)
    Manufacturer: Kingston
    Serial Number: D52687B3
    Asset Tag: Asset Tag:
    Part Number: TSB1600D3S11ELD/2G

dilemma:
i have found kingston blue. i am not sure whether to purchase it.
the details of it can be found @ http://www.kingston.com/en/memory/hyperx/blu.
almost all the memory modules details contain the following info:
number of pins, synchronous, ecc or non-ecc, & voltage, steps [ for
eg. 2 gb = 2x1gb ].

questions:
without opening the laptop where can i find info about number of pins
& voltage capacity of my memory module ? [ i am scared to open laptop
].
is Error Correction Type is also known as ECC ?
is it safe to purchase kingston blue ?
if my present ram type is sodimm, should i purchase only sodimm or dimm ?
and is my pre-installed ram is ddr3 ?
where can we find details about whether is memory ddr, ddr2 or ddr3 ?
some memory modules contain SDRAM in item details, what is the
realtionship of SDRAM with ram ?

thank u for your patience & i am looking forward for your guidance & knowledge.
war_dhan.