We generally do not recommend using spacers over having the proper offset rims, mostly because the cheaper spacers that most want to run instead of getting the proper offset rim are not hub centric spacers so this puts all the weight of the wheel on the studs instead of mostly on the hub. The wheel spacers that we do recommend (if this is the only option for the specific application) is true hub centric wheel spacers, depending on how wide of a spacer you are wanting to run these can range from $85-$200 per spacer, you generally need 4 of them so sometimes it is better to just get new rims and a few times it ha actually been cheaper. If you do go the hubcentric wheel spacer route you will want to make sure you retourque the luf nut holding the spacer onto the factory studs at minimum after 100 miles and 500 miles when you first put them on, and then every couple thousand mile or when you rotate your tires, we have seen a lot of people forget to do this and it will work itself just a little loose and start wearing stuff improperly and prematurely.
With that said we generally do not recommend unless you have no other option or it is just temporary, we would much rather see someone run the proper offset rim to minimize possible issues, minimize the amount of maintenance, while still having the looks they want. The biggest non hub centric wheel spacers we would recommend using is a 1/4" anything over that you really should go hub centric and make sure you check them frequently as stated above for proper torque.
For every one who might be thinking of running a hub centric wheel spacer/adapter we have found the B.O.R.A wheel adapters are very good quality and not as expensive as most however they are still from $85-$200 each before shipping, there are other companies that sell wheel spacers that are pretty much the exact same thing for up to 3 times that amount, I have only seen a few that are less expensive and they are no where near the same quality. We do not sell B.O.R.A wheel spacers or adapters however a quick google search and you can find them, when we run spacers on our own vehicles (temporarily while waiting on rims) we never even think about using anyone else and it is never a permanent solution either.
Here are a couple pics of what a proper wheel spacer/adapter look like for reference for anyone looking into this as a solution.
Thanks
Jeremiah