Building on the assessment from @JDRoberts, the other consideration I didn’t see in your original post was cost considerations. All bulbs in a fixture need to be replaced if you opt for smart lighting via bulbs (~$15/bulb for basic white), therefore bulbs are a good solution for individual lamps without a central light switch. If plug-in light fixtures have more than 2 bulbs then more cost effective solution is a controlled outlet (~$30-40). Finally, if several lights are controlled by a hardwired wall switch (single, 3-way, or 4+ way), then replacing the switch is the best solution (~$35-50, with addon switches ~$20).
Here’s where the planning gets technical. SmartThings communicates with 2 standard wireless protocols: Z-Wave and Zigbee. If you search the forums you are bound to find multiple discussions of these competing protocols. SmartThings, and other central Smart Home hubs, use these wireless protocols to directly communicate with devices rather than over an internet-based communication (i.e. no internet connection, no integration). Both protocols serve as wireless repeaters for other devices based on the same standard, so ideally try to build your system around a single wireless standard. Unfortunately there aren’t always equivalent devices available for both standards.
Zigbee: primarily light bulbs and presence sensors. Switches and outlets are available, but are more expensive.
Z-wave: Most device categories are available in a Z-wave variant. Outlets and switches based on z-wave are available from many different manufacturers.
Phillips bulbs are worthwhile if you want tunable white or color adjustable bulbs, but if you only want basic soft-white or daylight bulbs then try the Cree Connected bulbs. Tuneable white lights are nice to have in the bedroom, but they are not budget friendly.
As for switches, I’ve had the best experience with the GE line of switches. GE makes Z-wave dimmers (12724), switches (12722), and add-on switches for 3+ way circuits. If you require a Zigbee repeater, they also make a Zigbee dimmer and switch that work with the same standard add-on switch.
Another consideration is that Z-wave Plus devices (the new version of the Z-wave protocol) are becoming more widely available on the consumer market. The main advantages to the Z-wave Plus standard is range and reduced battery usage (not an issue for wired devices). GE has Z-wave Plus variants of their switches in the pipeline, but their availability is limited.