Our 8year old deck has some split boards and is pretty rough. We need to get 3more years out of it.My husbands idea is to sand,fill and then paint.we've looked at the deck restorer,but it looks like the
Texture would be to rough. Any sugestions.

Once the planks have split there is no going back. You could do some selective sanding and then stain or seal, but all this would to is get rid of some of the possible splinters. If you really want it to look good, then do the minimum now so you can save up for new decking.