Phantom power is necessary for most condensor mics (like the Octava) and ribbon mics, but not dynamic mics (like the SM57 and AKG D112).
You can look at getting a dedicated Phantom Power supply (as cheap as $35 a channel for the ART solution, up to a hundred a channel for high-end solutions), but if I were you, I would consider a slightly more expensive mini-mixer that will provide phantom power and oodles more flexibility, such as Mackie's
Tapco 6306, which is $120 and features modest EQ, 2 sends, headphone outs, 2 channels of phantom power, 6 channels total, main outs, control room outs, external device inputs.
Of course, you can go with more deluxe solutions, but for $120, you will get a little audio toolkit.