Wheel set consideration
If the bike is used mostly for training, you'll probably want to give high priority to reliability. In general, more spokes is better than fewer both because they're stronger and also because they're easier to true; 2-cross (or 3-cross) spoke patterns will be stronger than radial or "mixed" spoke patterns (for example, radial on one side and 1x on the other); rims with eyelets will be stronger than rims without; clincher rims will give you more choice about heavy-duty or puncture-resistant tires and tubes than tubular rims; aluminium rims will be more cost-effective than carbon; standard round spokes will be easier to find replacements for (should you need them) than bladed spokes.