XSL plug-in or IDE

Hi,

I am looking for an existing XSL/XML/Java IDE
or Eclipse plug-in.

My requirements are not high:
- visual editing or at least Preview (and better debugging) of XSL
(XML/XHTML) forms,
- good to have XSL/XSLT debugging;
- some integration with JBoss3 [3.0.7];
- support Java [JDK 1.4+], including debugging.
- (maybe) support of Cocoon 2.0.4;
(Editing Cocoon sitemaps is very nice but not required.
I am working on enhancing existing Cocoon project,
not doing new projects).

I use Eclipse [with MyEclipse] and XMLSpy.
Maybe XMLSpy plug-in for Eclipse is the answer ?
 But I don't see it showing HTML page out of XSL form at all,
nothing in its Browser tab.

Can anybody compare Lepido plug-in with XMLSpy for my requirements ?

Thank you in advance,
Oleg.