Cost cutting vs. reality
You will definitely need to go with glow for your first plane. You will not be able to find a good gas engine small enough for a trainer airplane. The smallest good gas engine that I see on TowerHobbies is about 2.1 cubic inches, and you about a .40 cubic inch engine for an average size trainer. Once you become efficient with the trainer and a few others, you can move up to the gassers.