Shure SM7DB XLR Interface and where to buy?

Hello everyone 🤗

Hopefully this is my last post I finally have the money for the mic and I just want to make sure I'm doing everything right.

Does it matter where I buy this mic? I see websites like sweetwater, Amazon? Or should I play it safe and just buy the mic on the shure website?

Also which XLR would be good to get for a streamer, entry level possibly voice acting. ( Yes I know it's not the best mic for voice acting but I'm mostly streaming probably will get mic just for voice acting later). Is the elgato wave good? Or maybe the focusrite? Also I realized you don't get a cable with this mic where should I buy that?

Sorry for all the questions but thank you if you do respond 💜