I've been following this "Revamp" mod for SupCom 2, which basically rebalances things a bit and adds the original SupCom 1 units and buildings to the game. There's an early beta out right now, but it's pretty poorly balanced from my experience, it basically just unlocks all of the SC1 units as a "tier" in each category (Air, Land, Structure, etc.). The way the SC1 units act though is completely faithful to the original game. It looks like it's pretty far off from completion, but it may worth be checking out in the future.
http://www.moddb.com/mods/revamp-modAs a person raised on Total Annihilation, the problem I had with SupCom 1 was that the design was so schizophrenic. In FA there were 4 races, but no race really felt unique or consistent. It seemed like they made a large group of units designed for each race, then shuffled them all and distributed them randomly among the 4 factions. The only place you really saw each race's unique feel was in the T4 units...ironically the least-used units in the game.
SC2 was a lot better in my opinion, though a bit oversimplified. It could have been great, but Chris stopped supporting it the same way he does for all his games.
If you guys loved Supreme Commander 1 you should really come try Balanced Annihilation in Spring RTS. Total Annihilation and SupCom 1 have a lot in common (Supreme Commander was supposed to be the "spiritual successor" to Total Annihilation after all), so you'll find yourself at home with many of the same playstyles and strategies as before. The only key differences I can think of is that there are two races instead of four (though I like to think the two races are much more well defined), there are no "Sub-Commanders" (I never understood the point of these anyway), and there are 3 techs of units instead of 4.
You've still got a Commander, metal (mass) extractors, energy collectors, geothermal powerplants, tiers of units, metal makers, engineers, etc.
The Tactical Nukes still exist, though they've taken a bit of a different flavor than before. Core gets Tactical Nukes while Arm gets EMP Launchers, which disable everything in a small area for 60 seconds. The range of the EMP launcher is 50% larger than the Tactical Nuke, which makes it better in many situations and keeps you safer while using it.
One thing I like a lot more about Balanced Annihilation than SC1 is that the Tier 1 units stay useful all game long. Obviously they're never as useful as they are in the early to mid-game, but even lategame if you have enough of them (and use them correctly) they can be really powerful. One of the additions I hated most about SupCom was shields. Even in FA, I felt like they just made the game into a turtlefest because they could basically repel a weaker attack indefinitely, forcing you to tech up every game to even make a dent in your opponent. BA has shields, but they're really expensive and they only block Kinetic weapons. This means they're good against long-range artillery and some ground units (like Tanks), but they won't block missiles, lasers, bombs, or Nukes; in other words, they aren't the end-all defense and they don't completely negate lower-tier attacks.
So anyway, if you loved Supreme Commander and haven't given Balanced Annihilation a try, I would highly recommend it. In my opinion it's the best ground-based RTS on the market today. It's very critical thinking and grand-strategy based, while still managing to keep the importance of micromanagement to only a moderate amount (compared to a game like Starcraft for example). All of the map content is made by the community so you'll never run out of different battlefields to play on, and the mod is being constantly updated and balanced by the developers. It can also support up to 16 players at a time and has a consistent number of people who play it.
edit: I forgot to say that because of the different economy and unit mechanics, the action starts a lot faster in TA, and stays exciting for most of the game. This obviously depends on the players (there's nothing FORCING you to fight after all), but in general, the games seem to be a lot more involved.