As one view (many have other views) I see even the best testosterone boosting supplements as being important for some for libido and how they feel. Alpha Male is the premier product for this.
However for muscle gain, especially for a young guy who has no particular reason to suspect testosterone problems, test boosters generally are not important and can be left out of even the most ambitious program.
As illustration, it’s well known and thoroughly demonstrated that low doses of even injected testosterone don’t really do that much for muscle gain. It takes relatively large doses to see major difference, and even the best boosters of natural production don’t give those kinds of increase.
It is worth making sure that diet provides the support needed for testosterone production. The main area of possible deficiencies are zinc, or a diet that’s misguidedly low in fat (less than 30% of daily calories.) ZMA or Elite Mineral Pro will take care of the zinc issue, or if red meat intake is high, that would already be taking care of it.
For best results in this quest for rapid mass gain, your brother’s choice of MAG-10 and Plazma would also be the right choice for you, combined with keeping your overall protein intake relatively high (about 200-300 g/day,) being sure to get sufficient caloric intake, and training hard and smart. I particularly recommend Christian Thibadeau’s training articles for training. Flameout will be valuable also, as it’s difficult to get sufficient DHA intake from food alone and in many cases, inflammation will hold back muscle gain.