Getting some good ideas in here so far.
I see you are running creatine and betaine (great combo) and looking for more, what made this combination so popular is the synergy between them, one of the first legitimate ways we have actually improved upon creatine supplementation.
Supplement synergy is something we took full advantage of in Ergonine, where even with that Creatine/Betaine combo we took it a step further with the addition of the new star on the scene Ferulic acid which has been shown to even further increase strength.
When you are supplementing with ingredients improving strength and endurance it is important to recover properly from the more intense workouts, so we included another combo of L-glutamine and l-alanine, l-glutamine has had long known potential but now we have the studies showing its benefits come through when in the presence of l-alanine.
Even further, quite possibly the most important for active individuals is hydration. Muscles grow in a hydrated state, fat is lost in a hydrated state, performance is improved (immensely, where 5-10% water loss comes with large statistical performance drops) in a hydrated state.
So we added our hydration complex including glycerol. Our reviewers seem agreed that it s so effective it adds an all-day muscle fullness effect.
Even further I see you have ARA on deck, Ergonine includes your carnitine salt (LCLT which also helps with your recovery) as well as glycerol to enhance your ARA effects.
For under $1 per day Ergonine is one of the most scientifically backed effective supplements loaded with bodybuilding staples at an amazing value.
I hope you check it out at athletixsports.com or read some reviews here to consider adding it to your stack.