hey mate, good to hear you're sprucing up your 4k.
with webers you'll find it depends on the person you talk to. personally i'm going to run 32/36 DGEV Weber, but i've been told over and over its too big, but i got it for free so you know can't complain. i've heard that 28/32 DCD is the best i think. I THINK. but really if you're putting a cam and all that stuff in basically any carby off a stock 1.5 or so litre engine should do fine, once again i'm no mechanic but from hours and hours of trawling rollaclub and other sites this is what i've come across. or you can go down the twins road and run twin webers or twin 40s but thats a fair bit of work and money and i don't know much about that. Except for the noise that dellortos (twin 40s) puts out makes me happy in the pants.
um, most carbies will fit with an adaptor plate from redline, my 32/36 one cost me about 40 bucks
with the cam, i've only had experience with Tighe Cams, but you can also have a geez around Crow Cams and Camtech (not sure on sites for these guys)
but with tighe, i've been told from tighe and others that the Tighe 113 grind is the best suited to a 4k with limited mods (no need for modified valve springs). i'm getting the tighe 104 which is a bit more aggressive as i've done some head work on the ol girl.
other than that go for gold, i can tell you tho, the build will snowball haha i went from just putting a VRS kit through my 4k to a full rebuild new bearings, new rings, some headwork, new evrything (water pump, fuel pump etc etc) haha, i got bitten by the "might as well do it while the engine is out" bug ahha.
good luck