I would either buy on that can be serviced widely or I'd rent one for the trips.

Renting rafts isn't inepensive if you do it more than occasionally. If you have your own, and have it serviced by a reputable group that you can trust, I'd tend to feel better about it.

If you simply shop around for someone that's going to rent you one for the lowest price, make sure you use reputable groups only.

There's that old Jerry Lewis and Dean Martin joke from a movie where they played guys that suddenly were paratroopers (without real training)...

Jerry Lewis says: What happens if the chute doesn't open? ;

Martin responded: Don't worry, if it doesn't open, then your emergency chute will save you;

Lewis: What happens if your emergency chute doesn't open?

Martine: No one has ever complained about that.