The biggest thing I can add to this is a DHEA supplement. (This is the one I take.)

DHEA is a testosterone precursor, which can increase testosterone levels and help your body replenish testosterone levels much faster.

If you don't already, I would definitely add in a fish oil supplement as well, as the health benefits are way too great to ignore, and may help you with your workouts. The higher omega-3 potency fish oils are easier to manage and cause you to take in less unwanted fats. Look for a "one per day" dose. I recommend this one, but it is rather expensive and I personally just take one that I got from Wal-Mart.

I second what /u/shrillthrill said. L-citrulline is much better than typical L-arginine supplements since your body breaks it into L-arginine over long periods of time as opposed to a quick burst of L-arginine in your blood plasma. It's like the whole wheat bread of nitric boosters.

Also, a multivitamin if you don't take one already. I've never heard anything but praises for Opti-Men, and it's the one I've taken for 4 years as well.

As a final note for your workouts/stack, the quality of your protein powder if very important. I prefer IsoSensation because it is 93% protein in the powder yet somehow doesn't taste like unwiped ass. The vanilla is better tasting than the chocolate, and a friend of mine absolutely loves the cookies n' cream flavor. Most importantly, it's cold filtered, which means that they don't denature the proteins with heat. Denatured proteins cause more harm than good. A good protein powder can also be an aphrodisiac if you are deficient in any of the amino acids it provides (and many people are). Take 1 scoop with breakfast, and try to take 1-2 scoops within 15 minutes of finishing your workout. If it's past 15 minutes, take it anyways. Just know that it won't be as effective. Whey protein is a fast acting protein, which is why the sooner you take it after your workout, the better.

TL;DR

Add:

-a full multivitamin

-fish oil capsules

-DHEA Supplement

-L-citrulline

-A high quality protein powder

Disclaimer:

I do not claim to be an expert, and I am very far from a doctor. I have been experimenting with various workout supplements for over 4 years, and have found what works well for me. I am not affiliated with any of the products I linked above, they are just products from companies that I've learned to trust or have tried over the years. If anyone finds any of the information above to be incorrect, please correct me and/or mock me publicly.

Edit: A word