dont go for one of the big named manufacturers. they are all crap. the mass market wheels are all too heavy and badly made.
the best wheels to go for are Rota, Work, Kei-racing, Volk, Compomotive. etc
bad manufacturers, Oz, Team dynamics, Wolfrace, Fox, TSW, basicaly anything you can go into halfords and buy off the shelf is a big no no. they are all ok, they are all acceptable, but in a 17" or 18" the weight of them will be hurendous.
my set of 15" rota slipstream wheels with tyres are light enough to pick them all up in one go quite easily. conversly an 18" oz TITAN alloy wheel on its own is far too heavy to even lift to your chest without some serious muscles.
go for some 17" rota's on toyo T1R's and drop it 30mm. you will not regret it.
and if you can afford them at the mo...... dont get them yet. save up.