This is not a question I am well-versed in because I haven't worked for a company that does commission, but I would say probably the one with the lower salary and unlimited commission because I know from what I've heard from other people who work commission jobs that it can be nice to be able to work that overtime and still get the commission. And since you're working in a sales job, commission can make up a big part of your pay, so I think I would prefer that.