I'm another who's learnt the lesson of cheap tools, split sockets and spanners with half a jaw, extension bars turned into corksrews and large chunks of my knuckles left on the corners of engine blocks!
Over the years I've built up a selection of Snap-on stuff - they are very expensive but I'm yet to break any of it, the sockets and spanners fit well and don't round off nuts and you can put an incredible amount of force on them.
8,10,12,13,14,17 and 19mm combination spanners and 3/8 drive sockets of the same size, a wrench and and 3" and 6" extension bar will sort out most of your problems. With 10 & 12mm being the most common sizes in the my Fronty engine bay.
Other suggestions are decent PH2 and 5mm flathead screwdriver an old knackered 1/2" wood chisel, a 2lb engineers hammer, a soft faced mallet, a 24" breaker bar, combination pliers and a a pair of long nose pliers.
Regards
TFB