BLACK+DECKER BDCS20C 4-Volt MAX Lithium-Ion Cordless Rechargeable Screwdriver https://www.amazon.com/dp/B00TM2T9C2?ref=yo_pop_ma_swf
Neiko 10048A Security Bit Set, Chrome Vanadium Steel | 100-Piece Set https://www.amazon.com/dp/B000O5XDOG?ref=yo_pop_ma_swf
I got this one.
https://www.amazon.com/gp/product/B00TM2T9C2/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1
If you need the bits too I picked up this set.
https://www.amazon.com/gp/product/B000O5XDOG/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1
It's bike stuff, so high power is your enemy.
You want the lightest, smallest device you can find. You don't want a drill, i.e. will you ever put a drillbit in it? You want a cordless screwdriver. No clumsy big chuck to deal with, slower speed.
The tiny little 4v (3.6v) pistol grip things are perfect for that kinda stuff.
https://www.homedepot.com/p/Ryobi-QuickTurn-4-Volt-Lithium-Ion-1-4-in-Cordless-Screwdriver-HP44L/205975772 <-- Random result, don't get this one in particular. But that kind of thing.
Ideally you'd have:
Variable speed (not just full on/full off, this is a necessity).
Impact (yes, they make impact drivers, half of what you do will be trying to snap out locktight fasterners, very hard to find in screwdriver size but they're out there).
Lithium.
And then buy 2, maybe 3 of them because: A - You'll lose one, B - You'll damage a charger and it's nice to have a spare, but keep the spare away until you wreck the first one, you'll alternate which is charging, and C - You will love the ability to swap drivers without having to change bits. Most of what you do will be 3 metric hex sizes.
And get a small grinder of some sort. As you eventually round over the tips on the bits, just grind some length off to where the stock is the right shape again.
https://www.google.ca/search?tbm=isch&q=4v+screwdriver <-- Take a scroll, most of those come out of the same factory.
https://www.amazon.com/BLACK-DECKER-BDCS20C-Lithium-Ion-Rechargeable/dp/B00TM2T9C2/ref=dp_ob_title_hi <-- $18. I have used and enjoyed this one, but I've only used a few so, for all I know there's other ones that are twice as good for the price. Take it as a passive "it doesn't suck" endorsement only, not a recommendation.
Something like this has been absolutely invaluable to me for building and repairs. Saves a ton of time and effort in the long run
A set like this also helps a lot for dealing with small screws on the motherboard and whatnot.