Spacered inwales are an elegant touch.  They are a bit involved to install, and might not be suited to first-time boatbuilders.  Detailed installation instructions are here, and are worth a read before you jump in.  

This kit includes pre-cut breasthooks (and quarter knees where applicable), mahogany inwale stock proportioned to fit your boat, spacer block material, and a pair of oarlock riser blocks.  Expect to do some trimming and fitting of the parts, as every boat varies slightly.