Beans are naturally flavored... unless you intend to sell crap. Those who do sell flavored beans may run a good business, but it has nothing to do with quality coffee. There's a HUGE difference.
<Mini rant>The same type of mindset would not care whether they sold their coffee whole bean or ground, they would sell whatever coffee was on their shelves regardless of how long it was out of the roaster, they would do primarily bulk drip coffee and/or really bad espresso on a machine they bought (new) for $4K and the only training they would have would be from the machine salesman. This, unfortunately represents about 90% of the coffee business. Still, many owners really don't care about coffee, they just want a "cool place to hang out and have a cup of coffee" rather than centering their business around the coffee/espresso they center it around the gimmick (low prices, cool chairs, bands, nifty artwork, naked barista, etc.) <end Mini rant>
An extremely short list:
Ethiopia Yirgacheffe -- Lemon, bright citrus
Brazil Cerrado - Chocolate and Marzipan
(many) Kenyan AA -- bright and or muted fruit (date, fig, plum OR berry, black currant, spice)
Specific farm/estate coffees:
Ethiopian Idido Misty Valley -- sweet mango, peach, lemon
El Salvador Monte Leon -- sweet baked pear and spice
Honduras Pacamara -Santa Marta-- cinnamon and sweet hazelnut
Costa Rica La Manita Tarrazu -- Peach, Vanilla, Apple, sweet florals
Panama Carmen Estate - Cherry peach apple.
Yemen Mokha Matari -- deep spice and dark chocolate
Point is coffee has over 800+ components inherent in coffee which work together to create wonderful flavors. If you want to claim anything about being quality at all, then let the coffee speak for itself. Source quality, properly roasted Single Origin and Estate/Regional coffees. Brew it properly [melitta, press, Clover] (no drip coffee), do regular cuppings, and no one would ever venture to ask for that low quality flavored crap.
The bar is set so low on coffee that by doing only what should be the minimum will put you in the top 10 percent. Hone your skills and source very select coffees, encourage whole bean only sales, never sell anything older than 1 week out of the roaster, etc. And (if you're doing it) understand all the ins and outs of espresso, freshness, grind, dosing, distribution, temperature, tamping, flow, extraction rate, extraction time, proper volume, machine cleanliness and maintenance, proper milk texturing, proper milk temperature.... etc. Along with understanding flow, efficient design, COGS, labor, utilizing low cost lighting, not wasting product, etc... running the business end well too,
and you will put yourself in the top 5%.
Do THESE kinds of things AND continue to learn by studying, practicing, tasting various coffees, visiting various shops, attending conferences, tasting and testing and more of the same... and you will put yourself in the top 1-2%.... but most don't have the patience, think about money first, sell an inferior product and try to convince everyone that it's quality, and most people, serving crap themselves, believe it is quality.
For me, success is determined by what's in the cup, and how much trouble will someone go to have it. Will they drive an hour for your coffee/espresso? Will they plan their vacation around it? Will they fly in? It's not possible to fail while running a Quality based business-- in ALL aspects of your business, and continuing to raise the bar as you learn more, and can do more. Hundreds fail every year because of low quality business skills, low quality product, low quality marketing, and/or poor location. There are many business models to choose from to achieve success, but choosing one that excludes or feigns quality should not be one of them.