I bought a £400 road bike (Cannondale) from Pauls at the end of 2015. Done about 5000km on it so far, just a new rear wheel because the original was a bit too cheap and not very cheerful. It’s been fine, including 100 mile days and 25% hill climbs. If I had the choice again, I’d buy a more CX-orientated bike, allowing me to dive off down tracks when I wanted.
Clothing – I wear the same as I do on the mountain bike (Ron Hills, Rab shorts, base layer, windproof top), but I’d echo comments about helmet peaks. Wasn’t too bad with my (10 year old) Giro, but the 7 helmet I just replaced it with has me thinking about buying a dedicated roadie lid.