You might be OK on a 53cm bike.....I'm 5'9.5", with a 30/31 inseam, and I'm riding a 54cm Scattante road bike, along with a Giant Medium frame OCR C2. I tried the 56's, and they were all too long of a reach. I tried the Cannondale Synapse, and it was a 53cm bike, which fit fine. The 56 was too big.....

I'd ditch those handlebars first thing, though.