What I know about Windows you could stick through the eye of a needle but I think that [link|http://www.object-arts.com/DolphinSmalltalk.htm|Dolphin] is aimed at Windows (uses native widget set).

There's also [link|http://www.objectconnect.com|Smalltalk MT]

You could check out IBM's[link|http://www-306.ibm.com/software/awdtools/smalltalk/|Visual Age Smalltalk].

Or, since MS claims you can host other languages on top of MSIL, there is [link|http://www.smallscript.com/|Smallscript/S#]. Its not a true smalltalk but it has some of the benefits.

[link|http://www.instantiations.com/sts/links.htm|http://www.instantia...com/sts/links.htm] is worth a look.

You can always approach Cincom if the license is a problem - they can be quite flexible these days (not like when PARCPlace had it).

The hosting in a PowerBuilder window bit - that's a bit weird though. I don't know if any of them can do that kind of integration.