Yukon wheel fitment

[99'Yukon]

I have a 99 Yukon SLT 2wd which has the 15x7 5 lug stock rims on it as of right now. I was looking online and found that the older 16in sawblade style Chevy/GMC rims might be a cheap way to go as far as giving the yukon a bit of a bump up in the air with some nicer knobbier tires on them.(I also like the look of the sawblade style rims) The only problem I have noticed on most of these older rims are that they are all 6 lug. Is there any way possible to somehow convert my 5 lug hub set up to a 6 lug set up so these rims would fit? Are there bigger sets of tires that would fit the 15x7's that I already have on the vehicle? Sizes? Any comment on this topic would greatly help me decide on wheels/tires. Thanks for your input!