Bluetooth device discovery

Hi all, I am doing some R&D for a new software app. Bluetooth with be used for communication between two computers. What I am looking for is a dll/SDK that is a universal blue tooth device discovery kit. 32feet .net is free and looks easy to use, however it only supports the windows blue tooth stack; which is no use for me. I'm not going to write an app in c++ if there is something already out there. I have come across two SDKs, those being the following: http://franson.com/bluetools/ http://www.filetransit.com/files.php?name=Widcomm_Bluetooth Does anyone have any experience with these, good bad? Also if you know of any other SDKs it would be great. I don't mind buying the kit as it would save me alot of time and hassle. I will be working in c#.net on VS 2008 in the .net framework 3.5 Any help would be greatly appreciated, Regards, Seamus