I've come across toning in my lomi lomi training (and crystal training), though never the use of singing bowls with lomi lomi. I've had lomi lomi therapists chanting/singing during treatments, and that was encouraged during most of the training I've done.
Temple style lomi lomi moves so much on an energetic level, I'm wondering why you'd want to bring in more energetic aspects like singing bowls?
I use stones, sometimes - many of the basic LaStone routine moves are VERY similar to lomi lomi done with the hands, using stones while you use your forearms temple style seems pretty difficult to me, ditto shells and bamboo. Wooden sticks are used in lomi lomi traditionally, and stones are used as a heat source for poultices, not so much as a massage tool. There are lots of hot stone massage routines saying they are Hawaiian/lomi lomi, but it's BASED on lomi lomi strokes, not a traditional method, (massage tables aren't traditionally used either ).
I've been amazed at how similar many Ayurvedic, Native American and lomi lomi massage styles are, so maybe the singing bowls aren't such a leap.