Depends on how far afield you wish to go, but some suggestions are:
1. Rothesay (The Black Bull inn does simple, cheap but good food, right opposite the pontoons).
2. Holy Loch (Try the Holy Loch Inn, just turn right and head up the hill 50 metres from the Marina).
3. Tarbert, Loch Fyne (The Victoria is the traditional pub for sailors, but the Anchor, now under new management, does great food).
4. Otter Ferry (Loch Fyne) has a new pontoon next to the Otter Ferry Inn (Haven't eaten there, so no idea about the food).
5. Lamlash on Arran - no pontoon, but as long as you avoid 2 hours either side of low tide (Springs) you can tie up alongside the pier. Try the Glensile Hotel (Turn left at the end of the pier, it's about 300 metres down on the right hand side of the road), the food is excellent, all freshly cooked. The Drift Inn is also a popular venue for yachites, but it is a bit "spit and sawdust", with cheap pub fare.
At Tighnabruich the An Lochan (used to be called the Royal Hotel) is worth a look, but it is expensive. However, do not leave your boat alongside their "pontoon", it is lethal and will quickly cut even the strongest of tubes to ribbons! Better to tie up alongside Tighnabruich Pier and live with the 15 minute walk to the hotel. You can also get pub food in the An Lochan's bar, the Shinty Bar, but it doesn't have the great views down the loch that the restaurant offers and it is still quite pricey.
Hope this is useful for starters. If you launch from Largs, you will see our boats (the big orange Humbers), so please do say hi if you are passing (I'm Jim, the good looking one!!!).
p.s. Getting petrol is a real problem on the Clyde - the only places offering dockside petrol are Largs Yacht Haven and Holy Loch Marina. Having carried 480 litres in 20 litre jerry cans at Tarbert on Friday, I can tell you it's a real pain in the neck (and back)!!! However, I'm sure you burn a little less than our 85 lph, so you can probably make use of local garages.