I'm working on giving my squier bullet a face-lift. It's a spare I have in the closet, but I do play it from time to time. I'm painting the chrome hardware flat black then I'm replacing the bridge pick up with a humbucker, which naturally will involve a new pick guard. I'm debating if I should buy new tuning machines or just lube the ones that are already on it. Does greasing up the inside of the tuners make a difference in how well they keep the strings in tune? If so, what type of grease should I use? Also, what's a decent, cheaper humbucker I could throw in there just for fun. I know it'll fit since there's room for one underneath the pick guard. Any other suggestions on how I can beef the bullet up? I know it's a cheap guitar, but I'm willing to put a little into it just to have it around as a spare.
Lubing it up will probably cause the tuning stablilty to just jump out the window and die. You may as well just get some new tuners.

And you could look at GFS pickups in the US, which are quite cheap, or if you go on Dangleberry Music in the UK, you can get some pickups there which are cheap and have fairly decent reviews.
Cam Sampbell's my hero