www.gunsprings.com has the Springs. As for the other parts, I seem to remember that Beretta says they don't sell individual parts so you have to buy a whole magazine to get the part you need. I may be wrong and some other company may offer the part, so maybe somone else will help out.
Back in September I had to replace two floorplates on my 92 magazines. I called Beretta and ordered two floorplates, two followers, and two springs without any problems. They were quick in getting them to me, a week or so is not bad. I think that I spent around $40 or so for the whole package, including S and H.