If you are of the mind, use you fingers. You can use one finger (middle one works best) lube it up good, insert and use a "come here" motion. Make sure he is aroused or do this while you are giving him some oral or hand work.
Toy wise, I would need to know what size he is comfy with. But pretty much any toy with a G-spot type curve could work good. Same thing though, arousal is key to P-spot pleasure.
Don't forget the lube.