By using two, we share the load between them, thus doubling their capacity, or halving their load. In both cases, they become more reliable and are quite capable of charging the capacitors which follow. I like them for two reasons - one, they have shown themselves to be extremely reliable, and two, they have most reasonable prices. They are packaged in metal cans with a center mounting hole, and are thus easy to affix and cool down, using the case bottom plate as the cooler. Of course, there are more powerful models available.
Capacitors are a separate story.
Many are on offer, practically all of them will get the job done, but there's no doubt that good capacitors will impart better sound to the amplifier than low cost, low quality ones, no matter what else we may do. So, no money saving there. Well, that they are good is beyond doubt, but in my view, they are not half as good as some others, they are just more fashionable and have a much better marketing department. But you won't go wrong with Elna, series black and series blue, not to mention the Starget and Cerafine series. I have excellent experience with Philips caps, even those strictly commercial units.