Once you have your skimmer choice narrowed down as it appears you have, your skimmer space looks good....Might have to angle or maneuver the skimmer, but should fit....I see you gave yourself a little extra room.....The baffle heights should be 9-10"......this will set your water height for your skimmer......Not exactly sure what the operating water depth would be, but assume between 6"-8" depth.....I would probably cut my baffle to 9", but before making the actual cut list I'd do a little searching and see what most are running their skimmers as......
I would cut an 1" off my fuge, and give yourself the extra room in the return pump area....You have to remember the return area is a bit more vital than maximizing the fuge to a degree.....An affect fuge doesn't have to be huge, but you also have to consider your pump choices....Eheim, and maybe Al or Corey, or better yet Flower could refresh my memory on the pump we chose for her sump build......Mag is another alternative as well.....I like to leave myself room in the return chamber as well for heaters and what not......
Overall the design looks good, but it all comes down to what do you want......