Merry Christmas to you as well. Glad to hear that Santa was kind to you.
This tank sounds like it's too small for 10 corys. If it's the 16 gallon Aqueon bowfront, it's only 18.5" long. In that case, I'd do either a single Apisto and 8 very small dither fish (e.g., Neon or Ember Tetras) OR 6 Pygmy Corys and 8 very small dither fish. If you'd like to do a slightly larger dither fish (e.g., Cardinal or Black Neon Tetra), I'd limit the shoal number to 6 or 7. Also, because this is a relatively tall small tank (16"), get a dither fish that is a mid/upper level dweller (e.g., Cardinal or Black Neon Tetra), rather than a mid/bottom dweller (e.g., Rummynose or Glowlight Tetra). That will prevent overcrowding on the bottom. Also, avoid fish that need lots of lateral swimming space (e.g., Zebra Danio, Bloodfin Tetra).
You have the right idea about the heater. I'd go with a 100 W. I use Marina heaters, but there are other good brands as well. The filters on the kit tanks aren't very good either. I'd suggest an AquaClear 30.