you'll find that most single pattern 4x bolt patterns pocket the area between the bolt holes on the backside, so there's actually a bit more material in a dual pattern 4x wheel than in a single in some cases. either way, a good wheel from a good manufacturer shouldn't be a worry.
what wheel, out of curiousity? 15x6 wheels to fit 4x100 FWD cars are available now and really are the way to go - access to more, cheaper tires and no gearing changes. (click the link in my sig if you are interested).