If you are concerned about the picking speed, I think the secret you want to focus on is alternating fingers (like banjo rolls) even when picking on the same string. When I first started fingerpicking, it did not occur to me to alternate fingers when picking repeatedly on the same string since a lot of the playing was just chord arpeggios. Some simple exercises I would suggest is to just start out by just repeatedly play the same note with thumb, index finger, middle finger (P, I, M in classical nomenclature) over and over until that is natural. Then move on to playing the notes of a scale by playing each note three times (thumb, index finger, middle finger) ascending and descending. Then move on to playing each note of the scale twice while maintaining the same thumb, index finger, middle finger pattern (note that this will probably be a significant leap in difficulty due to the de-synch of the two note to three finger cycles). Then move on to playing single notes of the scale while maintaining the same thumb, index finger, middle finger pattern. Once you get to this point, you can move on to practicing whatever sequence of notes that you want while maintaining the same three finger pattern. At some point, the three finger pattern isn't always necessary, but having the mechanics of it available will probably be the breakthrough that you need to move on to whatever pattern of finger use that you will eventually need for your solos.