I have owned this machine and if you are missing the hoop, you can find a replacement on ebay, or Amazon, or other places. The machine only does 4x4 , but you can also use a ''repositionable" hoop to do 5x7 designs by stitching part of the design, and then reposition to complete. However, you would need "split designs" or split them yourself with specialty software.
May I suggest you buy the Brother PE Basic card reader/writer instead of design cards? You can then download designs from the internet---free or purchased--and transfer from computer to the 'Basic' card to use in your machine. The Basic comes with software & reusable card--will hold many designs at one writing. It should cost about $100 and available at Walmart on line, ebay, many sites. The design cards can cost as much for only one card. this is the way to go. Re: selling items on this site, I think not. Read the terms of this site. There is a strict 'no advertising' policy. Perhaps you could consider joining the Etsy site if you want to sell.