I am currently in the process of planning a RTW trip next for about 6 months starting next summer. My intended routing looks tentatively like this:

ywg-yvr-hnl-akl-syd-bkk-sin-jnb-fra-cai-vie-ath-lhr-mad-eze-gru-ccs-mia-ywg

According to the Great Cirlce mapper this is 44000 miles. Is it possible to purchase any additional miles? I would really like to make this route happen. Also any comments or advice on the routing would be appreciated.