I suppose it depends on what you mean by 'groomed'. The problem is that any sort of trimming isn't normally done on this breed and hence that makes it very hard to recommend a good groomer when they all seem to have some weird and wacky individual idea in their head about how they will groom, I mean shave, a cavalier.
Many people here have had nightmarish results because groomers shave down their dogs or trim them way back, when the proper way to groom a cavalier is not to trim anything except the hair underneath their feet, between their pads.
If you want a cavalier groomed properly like this, I would write down exactly what you want and tell them specifically not to cut ears, feathering, or slippers and put the fear of God in them about it. basically tell them you want the dog washed and dried and not to put a scissors anywhere near the dog on threat of legal action.
If you want your dog shaved or trimmed -- then it depends. Most will do a hack job, in my opinion. On the other had some people like to shave their cavaliers and want them to look like this. In that case the majority of groomers will be happy to do this under the impression that this is how cavaliers are groomed.
So what I'm saying is (or rather ranting about in total frustration! :lol
, sadly very few Irish groomers (or groomers anywhere going by board experience!) have a clue about how to correctly groom a cavalier and will just shave them down, resulting in a dog that looks like another breed for months and months before the coat slowly begins to grow back. If this isn't what you want, or you want some sort of trim but not a shave -- then it's difficult. I'd still explain exactly what you want on paper and be absolutely specific.