Here is the url from Top Flite for the DC-3

http://www.top-flite.com/airplanes/topa0500.html

Based on their specs, I would suggested a couple of light weight .40 cu two-strokes or a couple of Saito FA-56 would sound great, IMHO. The wing loading is pretty high, so you will have to fly this plane carefully and all the way through the landing. Definitely not a floater.

SPECIFICATIONS
Stock Number: TOPA0500
Wingspan: 82.5 in (2095 mm)
Wing Area: 750 in² (48.8 dm²)
Weight: 8-10 lb (3630-4540 g)
Wing Loading: 24.6-30.7 oz/ft² (75-94 g/dm²)
Fuselage Length: 55.5 in (1410 mm)
Required: 2-stroke .25-.40 cu in or 4-stroke .40-.52 cu in engine & 4-8 channel radio with 6-9 servos (2 micro)