#1
I'm refinishing an old guitar, so far, I've stripped it down to the wood. It's an Epiphone Les paul and I'm having it white, with 2 big thick strips of black making a cross, and I might put some white stars in it.
Basically, a black and white version of this.

But the laquers I've been looking at are a bit pricey, can I just spraypaint it black and white with ordinary spray paint, then use a good clear laquer afterwards, cos that would save quite a bit of money, cos spray paint's only a couple of quid a can.
Gibson SG Standard, Gibson SG 60s tribute, Edwards Les Paul, Fender Telecaster, Epiphone SG Custom
#2
Depends on the finish you want. if you want a gloss style finish use a laquer,

if you want a matte finish (which IMO looks a lot cooler) buy Matte car paints (about £5 a can)
i'm Ginger its fun
#3
I dont think you need to break your bank on brands dude, I think it's more in the application, preparation, and post processing. If you prime it up good, sand between coats, and buff the clear you should end up with a solid finish regardless of brand... though I'd say I am partial to my Rustoleum lacquer. Before this particular lacquer though, I was a HUGE fan of Krylon, just saying.
Chain:
Fingers -> Schecter Damien FR -> Fulltone OCD -> ABY Box -> Bugera V22 / Peavey 6505+
#4
Acrylic Lacquer, as mentioned above, is pretty inexpensive, and hardens pretty fast. The palette of color is pretty immense. Just make sure to use Acrylic Lacquer for your Primer, ColorCoat, and Clearcoat, in short, the same family of finish, and you'll be all set.