Hi Nishant. Well I'm not an expert but hope that this help you.

Right now you have a very good offers of IDEs for Java. There is in the market two alternatives:

(a) Commercial: Borland JBuilder, IBM Websphere and many others. Usually this products costs some bucks, but if you can pay for them, good ;-)

(b) Open Source Products: I think there is a three most important tools or IDEs for what you want.
1. Eclipse: I use eclipse for my development in Java, I think is very good and more (www.eclipse.org). I feel this with a better performance than the others I will tell.
2. Sun One Studio Community Edition: this is a tool developed for Sun. This package has a commercial version that is more complete than this, but this CE is free for download. I think that this tool is good but but you need a good computer for run it in an acceptable manner.
3. Netbeans: Netbeans is the open source effort for Sun One Studio, in fact, they share some code one into another, so you could try this too.

All of this tools has the characteristics that you want. I think you could try all of them and make your own opinion.

For the second question (about Crystal) I remember that in an oportunity I did a search in google for this matter and I found some interesting links.

There are some sites that contains some classes that allow you make the connection between the Java platform and Crystal.

As I said before, hopes this helps.

Regards.