My guess is that those file formats are proprietary and we wouldn't be able to do that unless we were working with those companies. If you know any differently please let me know because it would certainly be interesting if we could provide those file formats.
I have a Silhouette SD machine and if you could make cutting files for it ... there is absolutely NO DOUBT I would be buying a BUNCH of them ... I really don't like cutting out by hand...but love to have my Silhouette do them ... and would make a lot of custom birthday and Christmas wrappings!!
The quickutz silhouette can cut GSD file types.
You might check ... you might be able to sell the designs through the Silhouette website because they have multiple designers ... but they don't get a lot for each sale ... but I bet they sell a TON!
There is a link where you could check out what you can or cannot do.... I had a 12 month purchased contract with them that just ran out this month. ... now I buy one at a time ...