Siemens E0816ML1125S Surface Mount, 125 Amp, 8 Space, 16 Circuit, Load Center

Does this subpanel support tandem circuit breakers?

I am planning on using this as a sub-panel and will be using # 8 gauge to feed it. when they say that a # 8 THHN can carry 40-45 amps , does this mean that if I run 2 legs ( two Hots) from the Main Service Panel with a 2 Pole 120/240 30 amp each leg, Will This give me a total of 60 amps for my Sub-Panel. Thanks

I am looking to replace the frame and door of my electrical panel it measures 14" x 31" Thank you

can I use cutler hammer CH type breakers?