It’ll partially depend on your artwork. Silhouette’s stamp kit is cool but it’s not great for fine details or lettering. Think of it as an computer aided potato stamp or lino/woodcut. Silhouette makes a different thing called Mint that’s excellent for finely detailed stamps. The machine is cheap and very easy to use but the supplies can be expensive.
Since you already have a GF lasering will give you more flexibility
And as @cynd11 said, your stamp pad can certainly be smaller than your stamp and work just fine. 