I looked at the retractable cover for my last truck. I didn't want to give up the space in the bed for the box. I agree with Chrisminx on the factory cover with the rambox. I really like it a lot. Great quality.
I thought I had posted to this thread but maybe it was another. I had a PE Jackrabbit for years and loved it. Just snagged a PE Switchblade for about $500. Hopefully next weekend I can post some pictures if it comes in this week.
I had a Retrax Roll and Lock cover on my 14 Ram 1500 with Ram Boxes and it worked great. The best price i could find was on Autoanything.com. If it is on sale or you have a code for a percentage off you call or do the chat then you can probably get the price a little lower. Every dollar saved can be used for more upgrades.