Matrix infinity and crystal chip are two of the best , or if you want a bit cheaper you can get a modbo which are clones of the matrix , but they work fine.
As for how hard they are to solder , well a slim isn't as hard as the older ones (don't have to solder to ic legs) , but if you've got little or no soldering experience , then it's still pretty hard. If you can solder , then it shouldn't be a problem.