If this person is looking to put their own designs and such "into an Embroidered design" then they need a digitizing program such as Embird to do this and learn to do this...digitizing is NOT Easy!!! takes patience...
As for Embroidery...buy the largest hoop size as you can. When you think you will only do 4x4 small designs, you will want to do the 5x7 an larger...measure twice and buy once...or you can look into the 6 needle machines...those are alot of fun...
Take your time, don't hurry and feel free to ask more questions.
K