Standard Chartered no longer change TCs even at the main branch, and Barclays only change them at the Accra High Street Branch but with a limit of 150 sterling a day, despite having the purchase certificate and photocopying my passport.
Coaches to Cotonou (Benin) go from the Chisco Station near Nkrumah Circle, the STC ones don’t stop in Acrra now. Fare is 90 cedis one way. The ABC station is in Carprice about 1/2 mile along the road from Nkrumah Circle towards Achimota, but they charge 115 cedis.
Best internet cafe in Accra is Cosby in Mompotse Ave, air-conditioned and a good fast connection, just opposite the Eclipse Hotel (recommended).
Your readers may be interested in this article which I wrote about my 2009 trip here: http://www.theprisma.co.uk/2011/01/17/moving-slow-in-west-africa/