Welcome to CoffeeSnobs [smiley=thumbsup.gif], hope we can make your journey through the world of great coffee both interesting and beneficial.
Re your question about the Sunbeam EMO480 Grinder.... from all accounts this is an excellent little grinder that will satisfy all your coffee-making requirements for quite some time to come. As to why you are not getting the sort of espresso shots that you would expect.... it is possible that the PortaFilter Baskets in your EM580 are of the "Pressurised" variety.
In a nutshell, great coffee and pressurised PFs do not belong in the same sentence together. I understand that there is an easy fix for this problem via the route you have indicated, re the Krupps non-pressurised baskets. One of our long time members, "mattyj" used to have a Sunbeam Espresso Machine (not sure which model) and he has posted many times about how to overcome the problem, so it might be worth your while to send him a Private Message and ask for his advice or do a search on the CS Forum to try and find relevant posts.
Hope this helps you out :),