The first tool you'll need is a copy of Kuhnhausen's Colt .45 Automatic shop manual. I would get that and read it before buying anything else.
The front sight will be a staked tenon type. That requires a
special tool. The rear sight, assuming it doesn't require a Bomar type relief cut into the slide, should be possible to put in without buying a dovetail sight drifting adjuster. A brass punch will usually do, though the adjuster makes it easier to be precise. The beavertail may or may not require a fixture for filing down the frame ears, depending on the design. Though they will prevent pinching of skin between the hammer and safety, I have not found the drop-in type beavertail really satisfactory as the web that goes between the frame ears on those presses into my hand about the same as the standard military grip safety does, and that gets old after enough rounds of hardball. I've had good luck with
Ed Brown's parts and tool, if you like his memory groove feature. If you don't, there's a Para Ordnance version without it,
here.
Most of the rest of the work you describe may be done with files, unless you want to do a trigger job. A trigger job involves some skill, and I'd recommend you let someone teach you that part, if possible. It's common for first timers to make errors that can result in safety hazards: doubling or the gun going off or the hammer following the slide when the slide racks a new round are the most common ones. It seems to me I went through three sears and two hammers before getting some coaching and learning to do a decent job. Would have saved some time, money, and danger if I'd got myself coached first. A gun that fails to let the hammer drop at all is at the opposite end of the spectrum, but it can be just as hazardous to your health under the wrong circumstance.
Hammer and trigger are up to you. In general, the lighter aluminum or composite triggers have a safety advantage over heavier steel. You may or may not want a long trigger. It depends on your hand shape. I like long triggers for bullseye target shooting (my Goldcup has one), but a short one for fast two-handed shooting. The long trigger seems to be in the way at speed. I like a Commander style hammer so I can run a lanyard through the hole while I stand on it. I use that to cock the hammer in dry fire. The super skeletonized hammers look cool, and I suppose they shorten lock time a little, but they lack mass, which puts ignition reliability at risk. Besides, you should learn to control the trigger press so that you don't disturb the gun when you drop the hammer anyway. If you need a few extra milliseconds off the lock time to stop yourself from yanking the shot as far off target, your fundamentals are already bent too far out of shape for reliable accuracy.
I have a flat mainspring housing on my Goldcup, but an arched one on my Gunsite school gun. I find the arch seems to help my hand find the correct grip position in the presentation (fast draw). Without it I sometimes plant my hand a little low on the grip frame. But, again, this is individual. You may have to buy a flat one just to find out. I prefer one with vertical grooves over checkering because I don't want my hand to slide up into best grip when getting to the gun in the holster. I'm sure others will feel differently. My only point is the function and your personal preference in that context should drive the selection.
