Pleather can be good for some things but with costumes like Cloud's I would suggest using some thing a little less shiny. His clothes tend to have more of a flat look. I would get light weight vinyl. Usually, it's with the upholstery material. It can be a little pricey but usually you can find a good remnant selection and get a really good deal. It's harder to sew than pleather. I would suggest using a leather needle on your sewing machine and heavy duty thread.
Here's a good pattern for pants if you decide to make them instead of buying them: 7918 Burda 7918 Mans suit. The guy looks pretty goofy but the pants really work well for all the versions of Cloud. For the Advent Children look I'd go with material for slacks or maybe a little thicker but his clothing seems to flow so nothing too heavy. As for the shirt you're going to have a hard time finding exactly what you need. JasonTerror has it probably as close as you're going to get it with out knitting it yourself. Another option...a really body boiling option is thick ribbed corduroy. You will have no air going to your body so you'll probably overheat but it does look nice. If you're still a little unsure of your sewing abilities I would say yes to buying gloves instead of making them. For all the zippers and random buckles that Final Fantasy loves go check out a leather store. They're usually pretty cheap and there will be a nice selection. Here's a good place to get all of that www.tandyleatherfactory.com
Sorry if this seems like too much info but having made a Cloud cosplay with my husband I know how challenging it can be with out any guidance.