My guess is that at 97dB sensitivity you are on the edge; probably fine without the DC filament power, but it's hard to predict - there are too many variables.
That's the main reason the DC supply is a separate item. You can pick one up later if you feel the need.
We generally encourage customers to build the stock kit first, and listen to it until it is reasonably well broken in - something like 100 hours of music, usually. It's far easier to debug a standard build, and the forum will be able to offer more help if there are any issues. Plus, if you do install any of the upgrades, you will be able to hear for yourself what effect they have.
Hopefully Doc B or PB will chime on on the tubes currently shipped.