I am able to instal mvcwt on my machine (also R 3.0.2). If you can't, it may be the mirror is not up to date. I always use the 0-cloud mirror (really rstudio.org) because it seems to be the most up to date.
For the second package, it should be install.packages('SynchWave')
. You had: install.packages('syncwave')
. I was also able to install this package for R 3.0.2.