Looking for tips on Weapon upgrades.

Weapons - Master-Spectre Gear (which is denoted by the prefix "HMW."  You can buy 1 round of it each at Level VII from the C-Sec or Normandy requisitions officer after you accumulate 1,000,000 credits (which unlocks the Rich achievement).  Sometimes a third round of it will open up as well.  After you reach Level 50, you can buy another round of Level X of it from each of those two requisitions officers.  It is really, really expensive; but without any doubt, the best weapons the game offers.  As for other lines of gear, just compare the various stats and keep trading up your inventory as you level up and the level of the gear you're finding levels up as well.

Armor - The best damage protection armor is the Colossus line.  The armor with the most shields is the Predator "LMH" line (which is not the same as just the Predator line).  Damage proection is better than higher shields, but both lines are more than adequate for getting the job done even on insanity.  Armor mods are a matter of personal preference.  Higher level armors allow you to equip two mods; and I like to eventually ensure everyone has a Medical Exoskeleton equipped in one of those slots so I don't have to worry about their health not regenerating.  I also like to make sure that each squad mate has one set of the types of armor that offer environmental protection (e.g. Explorer, Survivor, Liberator, Thermal).  When entering a world with a Level 1 hazard, putting 1 squad mate in this sort of armor will stop the hazard bar from affecting anyone... so you can stay out of the mako indefinitely.  When entering a world with a Level 2 hazard, this will slow down that hazard bar, meaning you can stay out of the mako longer than without any squaddie wearing such armor.  Since those lines of armor offer less damage protection than the Colossus brand and less shields than the Predator "LMH" brand, I never switch Shepard... just 1 of the squadmates... and generally the one I don't mind dying on me.

Ammo - These too are a matter of personal preference.  By the end game, I like to run with Level X Inferno Rounds equipped pretty much across the board with at least 3 of each other Level X round type so I can switch out either myself or a squad mate or all of us on the fly (but it's not something I do very much of).  I also keep some of the Level VII rounds (tungsten, shredder, cryo, proton,a nd polonium), even though I don't use them a whole lot, since you can't get them again after you pass Level 42.  Sometimes I don't collect all of the Level VII varieties depending on what missions I'm doing between Levels 37 and 42 (how much XP I'm getting quickly)... that is, sometimes I'm just not in that range of XP long enough to collect too many ammo mods at that level.

At any rate, your best bet is to just keep comparing the stats you see for each item before you decide to sell it or omni-gel it.  Put your best weapons in your loadout, the next best in your squad loadouts... and don't let the spares hang around.  In ME1, once you have something with better stats, there is really no reason to go back to something with lower stats.  The behavior of the weapons is just not different enough to warrant it.   It gets a little more interesting in ME2 and ME3.

In Mass Effect 1, all equipment (armor, mods, weapons, biotic amps, omni tools) come in three tiers: crap, soon to be crap, and top-of-the line.

Best weapons are the Spectre gear weapons (HMWA, HMWP, HMWSG, and HMWSR). These come in VII and X ranks. You can buy them from the C-SEC Requisitions officer, or from the Normandy Requisitions officer. Spectre VII weapons unlock for all Shepards once one Shepard gets 1 million credits (the Rich achievement). Rank X unlocks when Shepard reaches level 50 in your current playthrough.

Best armor for Shepard is typically Colossus armor, available in Light, Medium, and Heavy variants. They start at rank VIII. They are rare.

Best ammo mods are typically Tungsten (anti-synthetic) and Shredder (anti-organic). They are available in ranks IV to VII. Hold on to these. Tungsten and Shredder are better versions of Armor Piercing and Anti-Personnel rounds. Polonium rounds are available from ranks IV to VII, but do not have an equivalent at higher ranks.

Weapon mods are a personal choice. Heat sinks are generally good at ranks I to III, but do not have an equivalent until Frictionless Materials appear at ranks VIII to X.

Note that all armors get two mod slots starting at rank VII. All weapons get a second weapon mod slot starting at VII as well.

The best Omni Tools and Amps are Serrice Council tools/amps. They are available at ranks VIII to X. They are rare.

The best armor mods generally provide cooldown bonuses. so Kinetic Buffer is good. Mods that give you health regen are also good (First Aid, Medical interface). At ranks VIII to X, Medical Exoskeleton mods provide both cooldown bonuses and health regen.


NOTE: If you have the Pinnacle Station DLC (not a good DLC), you can get access to a store that provides some random access to the best weapons, amps, omni-tools and Medium Colossus X armor.