To me, the 36" oven will take a long time to heat up, and I have never needed a 36" wide oven, even for Thanksgiving. I like the idea of having a small oven when you just want to heat something small, and having two ovens when you have two things you are serving that cook at different temperatures. Keep in mind that for a 48" range, you will need a hood that is 48" -54" wide, plus the proper 8-10"-diameter ducting for that hood.

You mentioned you are thinking instead about a wall oven. In that case, I would do two wall ovens plus a 36" gas rangetop. Note I said rangetop, not a range, and not a cooktop, but a rangetop. I wouldn't go smaller than 36" on the rangetop, because it's quite useful to have the extra 6", even if you don't use all 6 burners. On the other hand, if you think you often use more than 6 burners at a time, get a rangetop wider than 36", but keep in mind again you will need a wider hood too.

Also, regarding your reference to a Tuscan kitchen. Be careful about that. The American-style Tuscan kitchen is considered dated, and many people thought it was too artificial to begin with. If you are seeking a true rustic Tuscan kitchen, be prepared to eliminate upper cabinets, and use honed marble counters and butcher block counters that allow lots of etching, scarring and patina. Actually, many Tuscan kitchens today opt for ultra-contemporary Italian cabinetry; it's just the American romantic idea that a Tuscan kitchen have faux-painted walls, curly iron scrollwork, porcelain roosters and the like.

Electric wall ovens would be self-cleaning.

Gas cooktop + electric wall oven = cooking bliss.

ok so if I did a 48" dual fuel range, besides the draw back of the extra space and extra duct work I would need. Would I miss my gas oven, is there anything better a gas oven does over the electric. I thought I read that a gas oven better for cooking electric better for baking??
I think I like the look of a range with stove and oven together, as opposed to the rangetop with wall oven. But I am open to ideas.

A wall oven has some ergonomic advantages, IMO, because the top one, at least, is at eye level. Also you can put your pots and implements in drawers under the rangetop, which is very convenient. But I do think that function and practicality is the most important thing. If a range works better for your space than a wall oven, by all means go for it.

A gas range -- 30 or 36 plus an electric oven or even a speed oven (electric oven combined with microwave that can be used either/or as well as in combination) might give you everything you want -- the range, with a gas oven big enough for the major stuff and an electric oven for baking and every-day. The electric oven or speed oven can be put at eye level or under counter-- whatever works best for you.

Gas ovens have more moist heat and are better than electric for roasting meats and poultry and for baking breaads. These days convection gas ovens provide very even heat and many consider them just as good as electric ovens for baking.