I re-did my kitchen a few years back. I did not want to replace the granite countertops (expensive) so a reused the base cabinet boxes; but built all new uppers. I was able to completely replace the face frames on the base cabinets. So not exactly your situation and recognizing that a lot of this is personal preference – so in additional to many of the other suggestions; here is my $.02
In the Shop
You will be handling a lot of large sheet goods – an extension table for you table saw will be useful
Construction.
Pre-finished cabinet grade plywood for the boxes. I would
not use melamine. Personally I think it is a cheap look, very heavy, doesn’t hold up to moisture – however I did laminate melamine sheets to the bottom shelf for ease of cleaning (Also made all shelfs out of melamine)
Boxes are not difficult to make – but it can be a chore hefting large sheet goods around.
I do not like the look of frameless cabinets; mine are framed primarily because I reused the old base cabinets and due to some internal geometry I had to deal with on the base cabinet fixed shelfs. If I had to do it over (or was starting from scratc0 I would go with inset doors/drawers. IMO – the best look and sign of high end cabinetry.
You probably know this one already – but cathedrals point UP on the door panels. For wider panels res-aw and book match if possible.
Leave enough extra material extending from the back edge of the boxes to allow them to be scribed to the walls. I don't really like the quarter round trim strip "look" – IMO they look cheap.
As someone else mentioned - I also think a few large drawers on the base cabinets makes sense.
Extras
Incorporate raised panels on all exposed sides of base and upper cabinets – IMO a quality touch. And add trim molding (see below) to the bottom edge of the upper cabinets (also a nice little extra touch).
I added a plinth molding and “feet” to the base cabinets to give them a furniture look.
Consider used two different materials for contrast and interest (I use Makoree for the cabinets and Wenge for the island)