I think you should look to Clearwater paddling. A tour company that is very, very highly rated but also hire out sea kayaks I think. They are up in the far north eastern Islands (Shetlands / Orkneys) but do lots of trips too say Knoydart, which is where I would want to go as you can paddle round the coast and walk the rough bounds as well. Try to lay your hands on an old Trail mag from about 6 years ago as they did an excellent kayak / walking holiday route involving sea lochs that feed off each other with plenty of Munros and the tother smaller ones too. Three dayer I think, but It just means leaving your gear and going for more walks on the extra days.
Of course a purely sea kayaking trip worthy splashing the cash on is round Jura. I know many who have done that and quite simply it has everything. Loverly wild camping, cave sleeping and whisky diistilleries to tempt even the most Methodist of you (no offence meant).
And one last thing, please make sure you really know what you are doing before doing any sea paddling. I am a whitewater paddler skilled and highly experienced after 20 something years of paddling yet I would not venture out onto the sea without someone with more experience of that type of paddling. I have some but just do not know enough about tides and tidal currents, etc, to do it alone.