I have never had any sucess using single shot baskets, on my old breville both pressurised and standard baskets, and on my giotto. I would just go with the doubles. Even if you get the pour time at about 30 seconds, i find the single basket does not give the body in the shot i enjoy.
FRESH coffee is a must once you try it for the first time but the flavour is a very personal thing so this is something that you will have to try for yourself. Just stick with the smaller boutique roasters and you cant really go wrong, just try their blends untill you find the one you like. Also, give some single origins a go, it is quite amazing how different coffee can be from different countries and altitudes, even if the actual variety of coffee is the same.