Alot of the answers are dependent on your personal taste, however, you should order the 7750 case plus a V72 caseback (you can ask DW if you can just swap casebacks, but, most likely you will need to pay extra for the extra caseback (ask DW for current pricing)). Since DW cases are made to nearly exact Daytona 62xx dimensions, they will accept gen parts. I use gen bracelets, crowns/tubes & crystals on mine. DW's dials, while far from perfect, tend to be the most accurate among aftermarket dials. If you prefer to go aftermarket for other parts, someone else will need to provide recommendations.
If you are doing your own mods, I would recommend that you use the Search tool & spend a good deal of time reading other members' experiences constructing these watches, as they can, depending on your luck of the (case) draw, be very difficult projects to complete. If you lack the tools/skills, I would seek out a reliable watchmaker who is willing to do the work for you (Ziggy comes immediately to mind).
Good luck.