I'd advise a proper Macro lens too.

Generally they're designed for as little distortion as possible and the greatest sharpness possible, the trade-off is generally a slower lens. You can use them for conventional subjects too - I have the original SMC Pentax 100mm f4 which I use as a plain 100mm lens on bright days as well as for macro stuff. Focus is a bit twitchy near infinity but it's ridiculously sharp even at f4, and brilliant for architecture.