There is a caravan site just outside of Brora but I just can't see an amusement arcade working. Brora's population is only around 2,500 and there isn't a massive influx of tourists in the short summer, rather an increase in passing trade as you're on the only major road serving the N.E.
Also, there may be servicing difficulties (call outs from Inverness?), a gambling licence required and the local churchfolk may object.
I've similar concerns over the laundrette idea,
Andy.
I know myself how hard it used to be to keep clean/dry when camping in the Highlands but these days most b&bs and camp sites offer laundry facilities to guests. A quick Google confirms that the Dalchalm site does this already.
In fact, the last laundrette in Stornoway folded (

) about 5 years ago as almost everyone now has their own machine, and our population is 10,000 in the town plus 1,000s of tourists.
An old friend of mine owned a laundrette in E. London (on big a council estate) and made a decent profit on it, but it was a real pain in the butt when the machines broke down. Vandalism was another problem if the place is unattended, too.
Set up costs can't be cheap, either, so I'd look very hard at your prospective profit margins before opting for this. Outside of the tourist months I really can't see you covering your operating costs and it could take years to recoup your initial expenditure.
I'd feel more confident for you if you found something which could generate a good income all year round so, again, think some form of eCommerce would serve you best.
What hobbies/interests do you and yours have (outside FISO!

),
Andy? Maybe there's something you already know something about or have a passion for which could become a business?
A wee idea ..... what about
Andy's Emporium or
The Coull Place?
Rather than specialising in one thing in particular, carry a range of essentials covering every activity which brings people to the area.
Do you remember the old General Stores we used to have in the 70s & 80s? They stocked everything from bootlaces to Bollinger (well, almost!

), packing a small range of all things imaginable into an Aladdin's Cave. They were almost magical places to visit when I was wee. I'm imagining a modern version .....
The quality food range idea still works well, but add to that:
Camping/caravanning essentials - a couple of cheap tents, pegs, guy ropes, travel games.
Cyclist's essentials.
Fishing essentials (

).
Golf essentials.
A few cheap waterproofs & wellies, hats and sunglasses.
A few binoculars and
monoculars for nature-lovers.
Various midge repellents/nets, bite creams, sun tan lotion (yes, it does shine sometimes), first aid kits,
Scottish soaps and such
Books - local history, Scottish nature, walker's guides, fishing guide, O.S. maps.
A bit of beach gear - bucket & spades, beach balls, kites, kiddies' nets, etc.
Local art & crafts, woolly jumpers, etc.
I'm sure you can think of lots more. The beauty is that you can hone your stock at minimum cost as you learn what the trade wants and then off-load any unwanted excess stock on eBay in the quieter months.
A bit of thought about the lay out could make the place very attractive and a wide range of well-sourced, well priced, quality products could offer something for everyone. Put an 'Ice Creams Welcomed' sign up so that the Cappaldi's trade can browse (out of the rain

) and you could become another 'must stop at .....' spot on the map.
Also, if you haven't already (though I'm sure you have), ask your friends and neighbours what they think the village is missing and what you could provide for them - surely some year-round trade is important?