If you think you're too old then you probably are.

[}:)]
I'm 52 and have been kiting for 10 years.
Kiteboarding is very easy to do but there is a bit of a learning curve. Lessons will help get you started but the only thing that gets you out and riding is a heap of practice.
It takes about 15-20 hours to get to the point where you can ride and stay upwind and generally relax and have fun. The faster you get that experience the sooner you will be riding. You need to commit to at least 3-4 2-hour sessions a week to get started fairly quickly.
The absolute number one key to success is learning to fly the kite automatically. You need to get your kite flying skills to a point where you can do it without thinking about it (and perhaps where you are patting yourself on the back about how good you are). If you can barely fly a kite then try to add in waves and a board it will end in tears.
A trainer kite is not a bad idea if you have any doubts about your ability to fly a kite.
At 95kg you want a 12m bow kite and a twintip of around 140x40cm. Up to 14m is ok if you want to go out in light winds. I am very partial to Cabrinha kites and the Switchblade is a good combination of performance and stability. You can get last years model quite cheaply, but the 2010 has a heap of nice improvements that are worth having.
Avoid very cheap kites from minor or obscure brands. The best way to choose a brand is to go to your local kite beach and see what most people are flying.