If your intent is to hide what you're doing from your LAN/ISP, there is a snag with Firefox. It will leak DNS requests locally unless you go to about:config and set "network.proxy.socks_remote_dns" to "true"
I was trying to make a shell script just the other day that would set up a SSH SOCKS proxy to a remote box and launch a browser using it, but couldn't do it from the command line in either Firefox or Chrome (didn't try a custom profile). Furthermore, I couldn't get it working in Chrome at all (shame; Firefox is more sluggish, and Opera won't even start on my box).
I'm unsure how to make it do remote DNS look-ups though.
Opera cannot do SOCKS.
function remotebrowse() {
export SOCKS_SERVER=localhost:5432
ssh -fNTD 5432 remote
google-chrome --user-data-dir=/tmp/chrome $1 &
}