bad idea to decide on receiver. Always...always choose your speakers first!!
The front 2 speakers are the most important in the whole setup. Pick them first. the surrounds play very small percent of the sound, most of the audio is reproduced by the front 2 speakers. This should be your priority. The center plays the part of dialog reproduction in movies. Subwoofer for the reproduce bass. You could then choose the center or sub next. And then lastly the surrounds. (the surrounds can be almost anything - they are important in terms of the effects, but their role is quite minimal)
You could buy a HTIB, but you can do much much better by buying the 2 front speakers and building around it. Bookshelves are ideal for your budget.
Once you have decided what your front speakers are, then you can choose your receiver such that they match well....to be more specific - so that the receiver is capable of driving the speakers. Some speakers are easy loads and some are difficult loads. So if you dont choose your speakers first you dont know how to drive them and how much power they will require. You can choose the remaining speakers after this.
You get really good bookshelves above 20K. Suggest you explore in this budget. I know of PSB's Image B6 bookshelves for front. The B6 is I think around 25-30K. The center will cost around 20-25K.
When it come to subwoofer...IMHO, dont make the mistake of picking any sub. Explore for HSU, Rythmik, SVS, Epik. *Most other* subs are not worth it (there are a few others like ED and so on...I listed more common ones....dont even think of Jamo, velodyne or so...you can get much better for the same money). So if you are letf with like 20-30K for a sub you might want to hold on until you can afford a gud sub.
What is your room size? Sub choice depends on room size, if room is bigger then it will cost you more. So dont jump into buying any sub.
Also, if your room is small, you might want to strongly consider front firing speakers....as back firing will require that you keep it a certain distance from the wall.
If you are compromising somewhere, compromise on the surrounds. Do not compromise on the front or the subwoofer.
