I'd thru-bolt them and plug the holes in the top of the handrails after. Hanger-bolts are still just a wood-screw into the teak plastic handrails, after seeing my Dad slip off the deck when he stepped on a jib-sheet and the thru-bolted handrail that he grabbed held firm as he grabbed it... I'd never attach a critical safety item with screws. One thought, the stainless-steel rails usually have the bolts built-in, I prefer the warm look of teak (and teak is often less $$ than the SS or Starboard versions), but the clean look of the stain-less rails along with the bolts being integral might make that choice worth considering. Teak is NOT hard to maintain, and actually.. requires just being kept clean to avoid problems. Applying varnish or other clear finish sure looks GREAT, but then does become an upkeep task. Raw teak will weather to a salty, grey color and the natural oils will protect it. A periodic cleaning with a soft scrub brush should remove any dirt without eroding the surface. We kept ours oiled (use teak oil and apply with a rag or small "chip-brush"), but even in Southeastern New England that oiling became a nearly every 2-weeks task. Teak cleaners/bleaches actually do more harm than good, as they chemically remove wood each time, we found a light sanding with fine paper or bronze wool worked best (about 1-2 times per year).
The ones from CATALINA DIRECT, made for the Cat-22, "might" fit, but calling them would get you a yes/no and price. However, I'd check at WEST or other marine outlets for something "off-the-shelf", since the Catalina ones are "semi-custom" (even if ordered for a Catalina) and so may be $$. I like that they are made to attach using machine screws (bolts) from below, the rails have threads cut in the bottoms of the legs (plugs welded into the tubing).
