Best Wheelbarrow?

I'm using my Dad's wheelbarrow. It's well over 55 years old. That's no exageration. It's solid metal throughout and has a solid rubber tire. Until now, nothing has ever had to be repaired and never a flat, of course. This past year though, a tiny 1/8" hole has rusted through the bottom. I inherited it when he died ('86). Because it's solid steel it's very heavy. The very thing that makes it so durable also makes your job harder when using it. Often the load I'm carrying is lighter than the weight of the wheelbarrow. My arms practically drag the ground after a day using it. I'm a senior citizen myself now and it's time to get a new lighter one. I'm looking for one that's a traditional wheelbarrow type, with a solid rubber tire, durable but light. Does any one even make anything like that? I work as a Master Gardener volunteer at our local botanical garden. They have wheelbarrows galore, but they are all falling apart in some way or other or they get a flat tire.
Any help or suggestions?