if I were you I will buy a decent 17-50 2.8 so I can survive w/ ambient light only. plus d7k ISO performance is. excellent! I like it
and get a decent flash like sb-600 or sb-800.
this case provided you have enough budget.
anyway get 35mm 1.8 might be a great idea as well.
a lot of people use that for their 1st paid shoot.

is my photos ok ah guys 

guys, can i achieve this color without any PP ?

what condition that should i meet in order to produce photo like this !

need some guidance 

how do u mean the exact exposure and WB 
haha. sorry la bro. my tfk hand always interrupt me to get a steady image.

i need to adjust in LR or in camera setting ah ? 

In addition, which rechargeable battery recommended to pair up with the SB900? Since I have gone that far, gonna get a good rechargeable batteries pack too.

I remembered I have read before that stating, "Eneelop battery is like designed for flashgun". I looked into Eneelop series, it has the new Sanyo Eneloop Harmolattice which is 2500 mAh. Would that be recommended? Again, the shop I bought the flashgun shared that their customers experienced that batteries above 2300mAh will spoils the flashgun. Wonder how much truth in this statement.

This guy is doing a promo of Eneloop 4pcs Harmolattice AA (2500mAh) with 2hr Quick Charger + 4AA/ 4AAA (2000mAh) at the price of RM149. Good deal? Any precaution?

get the correct exposure and white balance 

underexpose: colour dull
overexpose: colour washed out
white balance: too warm or too cold, colour not right

then no direct jpeg/raw pic straight frm camera can get that vibrant colour, even with vivid

but then cosplay event the WB will run off right? because too colourful already XD...
last time snap this my friend said the WB take her pink wig as WB ...and make whole picture become pink...
now i wonder how the WB judge the "white"
that picture PPed one.

^ 1.4 you say?

I'm thinking the same as well but my friends suggested me to take the 18-105mm coz of longer length and the image is sharp as well..

But i'm kinda stuck now.. lol

I tried my friend  AF 80-200 f/2.8D ED not bad mah
two touch version, but for me still a bit , a bit soft on wide open.
Maybe I too picky. I feel 70-200 VR much better though I can't compare them side by side.