Starting with one or two KB

I am just starting out with kettlebells. My question is would I be better served by ordering two 25 or 30 lb KB’s or one 35 lb. Was wondering which would be better for me just starting out.

I am 49 years old and in pretty good shape. Two years ago, I weighed 290 pounds. Today, I am 5′10" and weigh 167 pounds with 5.5% body fat. I lost it mostly by riding an old recumbent exercise bike and changing my eating habits. No surgery or special diets. Didn’t start weight training until about 14 months ago but have been consistently doing that for three days a week since then.

At this point, I am more concerned with increasing functional strength and staying in shape than bulking up at this point. I do have some issues with my left shoulder and elbow so I am concerned about going too heavy. In fact, I think that is part of my problem with my shoulder. Tried to macho up when it started bothering me when I was younger.

Any advice would be appreciated.