We did the Twin Islands Guided Kayak Tour (5.5 hours) when we visited in January and had an awesome time.
Special shout-out to our tour guide, Maggie! We opted for the guided tour as it felt safer than trying to navigate by ourselves around the "danger zone" in the waters, and we have no regrets; the wind and waves did feel pretty strong as we were heading out to the Mokulua Islands, and Maggie's kayak was a helpful reference when we started to veer off-track. Maggie's help was also much appreciated when we had to launch our kayak from shore.
The guided tour was limited to 8 people total and included a short walking tour and lunch on the Twin Islands (a sandwich, potato chips, Oreos, bottled water, and Hawaiian Sun). The company also provided snorkeling gear, but we decided not to snorkel at the Mokes since the water looked quite choppy.
Another perk of the tour was that we had the option to use any of their bikes or snorkel gear for the rest of the day after the tour. Several in our group decided to take the bikes out for a spin and head towards Lanikai Beach nearby, which is known for great snorkeling.
I recommend the Twin Islands Guided Kayak Tour and would return to Kailua Beach Adventures for more rentals next time I'm in the area.