Not sure if you’re still shopping, but to answer your question:
Get some of the short bands for deadlifting. They are so much more convenient and practical for the deadlift. I’m similar to you and Marlboro, 445 for a current DL. I’d definitely get a pair of the Monster Minis and the Lights. Works well on speed day for a 3 week wave of monster minis @ 50, 60 and 70%, then the next 3 week wave with the Shrot Light bands.
The short average bands are a bitch. They add around 175 lbs at lockout. I like them for an occasional ME day when I want to work against a ton of tension. My lockout sucks, so bands of all kind are a great help to my deadlift. But I actually like the Short Mini bands for ME deadlift days too. It overloads the top, while still allowing me to work heavy at the start.
Get the 41" bands (the regular ones) for squat and bench. Honestly, I find use for all the bands here, as the bench has to be doubled up so I need much lighter bands there between the double ups and lighter weights we all move on the bench anyways. On speed days, the mini bands doubled up can beat me to shit. So i typically do a 3 week wave of micro minis (maybe only 30 lbs added at lockout), then a 3 week wave of minis. I like to do 3 week waves with the monster minis and the lights for my squatting. On ME days, I like the lights and the average bands.
I realize I may have just recommended that you buy just about all of them. So if you’re on budget, I’d start here:
For DLs: Short Monster Minis
For BP: Mini Bands (doubled up)
For Squat: Light Bands (can use for both strength-speed and ME)
I don’t see any point in spending extra money for the Onyx (plus, I prefer the different colors on the standard line when I’m trying to figure out which mess to pull out from my trunk before going into the gym). Much rather have more bands at my disposal. All of the standard ones I bought have been pretty consistent in terms of calibration and show no signs of wear-and-tear.