You might find this interesting:
https://github.com/echolevel/open-amiga-sampler
It was posted a few months ago, hopefully they will see it through and make the boards available at some point.
Using an Amiga for audio seems to have gone a bit 'hipster' of late (see Pete Cannon's Sound on Sound interview on youtube) which has pushed up the prices of second hand samplers, unless you get lucky on ebay when someone lists a cheap one as buy it now. It's pretty disgusting that people are selling the likes of Stereomaster for £50+ and the quality you get from it is awful. Keep a look out for the GVP DSS samplers or any of the more substantial looking ones off this page:
http://amiga.resource.cx/search.pl?amiga=500&cat=sam
But even then, the best sounding option is to convert on PC and copy across, it's a world of difference.