There is no "Best course of treatment" There's no way to know how you'll respond to TRT until you start treatment.
I'm 47 and was diagnosed with Low Testosterone in March, it took me about 3 months to get over my denial, do a bunch or research and seek treatment. I just started taking Androgel 1.62.
Before doing anything else, you need to find a Doc that knows how to treat Low T. I've found that they are not easy to come by. If you tell me where you live I might be able to point you in the right direction.
Next, you need more lab tests. You need:
Free Testoserone
Estradiol, Sensitive
At a minimum. The complete list of what tests are needed and general treatment protocols can be found here:
http://www.allthingsmale.com/word_docs/TRT.doc
Most docs recommend starting with a transdermal like Androgel. Though with your low LH level you might be able to restart testosterone production with HCG.
As far as overweight is concerned, are you a little overweight or a lot? You might want to get off the carbs and check out a slow carb diet. I'm using the 4 hour body diet, but there are others like south beach. Getting your weight under control will go a long way to helping your health.
With work out's look into HIIT training. High Intensity Interval Training. The slow carb diet will take off the fat, HIIT will get you in shape, I'd cut way back on the cardio.
We have this idea that people who are overweight are lazy of have no self control, that eating less and working out more will make us in shape. The research just doesn't support this. I know it sounds a bit crazy, though it's proven true for me. Cutting out sugar, white carbs and other high GI carbs takes off weight like nothing else.
I'm not claiming to be an expert, just talking about my own experience and research.
Good Luck,
Eddie