Suggestions for ST-1 upgrades

[Andyxlh]

I'd agree with this, in order for me...
Bone nut
Roller string trees (both available on eBay cheaply)
Pickups tonerider for sure, there's different types for different styles of music. Great value from Pitbull. If he is a hard rock nut you could buy a loaded pickguard cheap from China with 2 humbuckers in it, eBay. The cheap humbuckers are pretty good imho, much better than the cheap single coils
Machine heads, Grover from Pitbull. Amazing value, I'll be replacing all of mine with these eventually. This might be number one depending on the quality of the stock ones, I have had great stock sets and ones that slip and have rough gears.
Bridge, wilkinson
Pots and caps... cts and orange drop cap from Pitbull

[Walrus]

depending on the quality of the stock ones

The stock ones on this guitar are actually ok - but there is enough movement in a couple of them to warrant replacing.