The fabric I used for this baby body is a tricot fabric called "Applelicious" from Poppy (this link is to the only online shop I could find who had this fabric, you can change language in the bottom of the homepage)
It does not take long to finish this kind of garment and I did not use any special tools to get a good result. This type of body only contains four pieces and the only things you should remember is to first use a narrow zigzag stich to prepare all the cut fabric edges and then use straight stitches to make the nice finish. You can also use overlock but I think zigzag stitches is just as good.
I thought the buttons Prym 10 mm Jersey would be difficult to manage but in the package I got a plastic stick which allowed me to get a nice look just by using a hammer!
So, my point is that it really is easy and you just need ordinary sewing knowledge to make this kind of garment, so if you are inspired just go a head and buy a pattern and some cute fabric and get started!
Have fun!