Just a couple things to consider when you're deciding what to get...
Paint vs. powdercoat - Either way if you use your sliders you'll scrape it off and rust will begin. You can touch them up with paint even if they're powdercoated. Personally, I painted mine because I knew they were going to get used and it looks better (IMO) to touch them up. Prepping them yourself isn't too hard - use something like Duplicolor grease and wax remover, scuff them up with some sandpaper, use a self-etching primer, then paint or use some bedliner on them.
Bolt on vs. weld on - All my friends who have weld on sliders say they wish they had bolt ons so they could take them off to grind and repaint or powdercoat again. If you're going to use them, like I said above the paint or powdercoat will get scraped off. If you get weld on sliders and have them powdercoated you won't be able to powdercoat them again later.