The Samsung 40D550 is pretty good (CCFL Backlit LCD). I bought one about 2 months ago. Your friend should get it for around 44-45K. I'm not completely sure, but I'm told there's also an LED backlit LCD (edge-lit) Samsung for just about 5K more in the 40" size.
I'd used another Samsung 32" LCD for 2 years and I did not have a single issue. So I really don't know about service.
As for the 40D550, I bought it form the Samsung showroom in Ravipuram and I found the guy there very helpful. Even though I bought it very late in the evening, he arranged for delivery and table-top installation (though I didn't need "installation") immediately. The Samsung guys called me up early the next morning and asked me if I wanted the TV wall-mounted that day. (I didn't need that). I'd also bought a 2-year warranty extension from the showroom, BTW.
The other shops I visited would give me delivery only the next day evening, even though I offered to transport the TV myself. They did quote a price about Rs.500.00 lesser than the Samsung Showroom price though. But I was more certain of getting a fresh piece from the Samsung showroom, and I definitely wanted the TV the same day, so I decided to get it from the Samsung showroom.
EDIT: The Sony EX520 is not available in Kochi. I tried talking to a guy I knew in Sony even, to see if they would get it down for me, but no dice.