Aled
Do you want any general comments? I'm touring Italy at the moment and I've spent a fair amount of time on the coast. Here are some comments:
- the coast of the Gargano national park is (mainly) very beautiful - comparable with the nort-west coast of Corsica. Don't be tempted to take short-cuts - even though this will mean extra climbing. Also there are several tunnels around Mattinata that are worth avoiding;
- the coast of Puglia going south towards Bari is less spectacular but still worthwhile. There are some lovely bits around the Salento coast. Otranto and Gallipoli are definitely worth exploring if you have time -as is Lecce.
- there's a chain of lovely coastal towns (Barletta, Trani, Molfetta, Polignano, Bisceglie, Monopoli) that are lovely but the dilemma for you is that to get the most out of the ride you need to go into the town centres )'centro storico') - if you stick to the main strada provinciale you bypass all the bits yhat are worth seeing. I'd be tempted to head inland thriugh Alberobello, Locorotondo, Cistenino, Martina Franca which are all on an escarpment 300 metres above the coastal plain;
- the SS16 is the main non-motorway road along the coast. I'm not sure how ling it is maybe 700 or 800 kilometres. The bits I've been on have been flat and with a good surface so even an idle slacker like me could get up a good speed on it. But it isn't especially scenic: for long stretches you ride between the railway line and the motorway. You might at points get to see the sea ... (I don't want to overstate the point - it's not necessarily horrible horrible, but i rode it for one day and I'm not sure I'd fancy riding it day after day);
- as you get further south the SS16 has been upgraded (locals call it the 'superstrada') and there's at least one bit (between Monopoli and Polignano) where you can't ride a bike - although you can use the service road ('viabbilità di servizio'). There may be other stretches;
- be aware that tourism in Italy can be highly-seasonal. If you are planning to go after (say) mid-September you may find campsites are starting to close for the winter. Do your research: definitely don't rely on the little wigwams on the maps - theyr're no guarantee that the campsite is open or even exists.
And as for what bike. Well if you have vehicle support then quite possibly the bike you already have. Wider tyres would help with some of the rougher roads, but there are plenty of Italians riding around on normal road bikes with thin tyres and they seem to cope.