Chapter 4 of the DRSSTC design guide is now online, the subject is on DC bus capacitors with a primary focus on the regularly used aluminium electrolytic capacitors. A comparison with film capacitors is made and calculations to help you ensure your energy storage will hold up for your DRSSTC use.
It can be a hard start to build a Tesla coil if you have no prior experience in doing so, I recommend that you watch my video on how I learned to build Tesla coils. I have also developed a good deal of tools that can help you design and check if your components can be used in a Tesla coil. It is important to stay within the physical and electrical limits of the components. Else you are at great risk of damaging them due to Tesla coils pushing the components beyond their specifications. We do this in order to get the longest sparks for the least amount of money.