hi from_india,
I got your PM as well.
So in reposne of that, If your offer is £ 38K , it is too less for London. If it is £ 46 K or £ 48K , then only you should come. So, get the things cleared with your employer on what is this £ 8K component.
Just get a feeling of how much you will get in hand on £38K and £ 46K/£48K from this URL :-
http://netsalary.blogspot.com
Your house expenses for 2 Bedroom Furnished House :- Around £800 GBP+. (Don't go for Unfurnished homes).
You have not included the Electricity , Gas and Water expenses:-
electricy :- £40 p.m
water and sewerage :- £ 25 p.m.
Gas :- £ 35 p.m.
Sky / cable TV subscription :- £15-£18 p.m
Broadband Subscription :- £ 15 p.m. (Tiscali , Unlimited 2.3 Mbps)
LandLine Charges :- £ 12 p.m.
No need for Medical insurance if your company is providing it, also NHS is free of cost.
Rest of your estimation is correct. I don't know how much luxury you want with buying a CAR as you have a KID of 2 years. With a high salary, you may be enjoying the luxury of a Esteem/ Wagon-R VXI in India

, As was the case with me,

. Although commutation in London is good, you may not require it and must not buy it till you get FLR. As getting a DL is very costly here.
My conclusion is, London is not a place to come at £38K, if you have £46K/£48K, then please come and enjoy. Make sure what this £8K is which you have mentioned.