I personally would go with Kingfisher, IndiGo and SpiceJet in that order.
The reasons being first and foremost, I am qualified and highly experienced on the A320, and SpiceJet only operates 737s, of which I don't have any time. Secondly, Kingfisher has very deep pockets financially speaking, whereas IndiGo I am not as sure of.
Vijay Mallya is one helluva promoter, and has plans to go international, whereas IndiGo doesn't at the present time. Kingfisher seems like, at least from this side of the Atlantic, to be a very well run operation, and hey, the Flight Attendants (at least in the pictures) are easy on the eyes! Monetarily, the two seem to offer the same package, but that may depend on which leasing service you go through as well.
Right now, from what I have read, Kingfisher has a hold on recruitment, but that should pick up again in 2007. There is a screening taking place in KUL on November 12th, but I'm sure if your friend hasn't already started his paperwork, it is too late for that.
I have been offered a screening for KF, but I'm still employed and don't wish to start any new adventures at this time. But if this market continues its spiral into the toilet, I very well may have to look outside the US.
All of the above is of course, my opinion only.
WW