wow
i am an avid guitarist-electirc and accoustic
as far as an SAK-id suggest a mini champ 1 or 2-the former being harder to find -the latter having the light and phillips- my exeperience in playing and building lutes and guitars is that smaller easy to control things are wisest around instruments for on the spot tinkering-both have small screw drivers and dull tools which may allow prising without scoring-=otoh-and SAK with flat, phillips, fine screw driver, and pliers would also fit the bill well-nothing wrong with a swiss champ-just hope its not in the case compartment and falls loose onto the guitars finish- i have to say in all my years- i use wires cutters, and a string winder-period-on the fly adjustments even for electircs are rare-once youre set up -things stay -set ups are best done on a bench
what id really suggest (but not as fun visually as a Red SAK-is a product made by Pigtail-here in Colorado-it is in essence a 'SAK" desinged especially for fender guitars but works just fine too on my gibsons and martin-
its got a string cutter, string winder to fit multi sized pegs , several flat and phillips, string peg puller and some hex wrenches sized to fit fender bridges and saddles-it has my essentials-winder and wire cutter
but it is an extremely high quality unit-hand assmebled and made here in colorado by an ex nasa machinest steve rowen-heads above everything else-excellent metal and top quality fiber / plastic body- no im not affiliated- i went to his quansit hut machine shop for some custom guitar parts and saw him work
bought 3 on the spot-and watched him personally assembling the units-hes a stickler for quality-and his stuff reflects it
there may be less expensive tools and kits you can get -in fact i know there are because i have some of those too-and these also have virtues-mainly dedicated tools -usually very cheap chinese-but adequate -were not talking auto mechanics or undue strain in this application
go to muscians friend.com to look around for these other options-
-Steves guitar tool is about $25- but the convenience of one single SAK type tool is nice-
not as cool but nice-