Hi,
The laborious way would be to select all (cmd+a), copying (cmd+c), fire up TextEdit and from its 'Edit' menu, choose to paste and match style (opt
shift+cmdv). Alternatively, if you have TextEdit set to format in plain text by default (so that it excludes graphics), you can make use of the 'services' submenu (under 'Safari') to create a 'New Window Containing Selection'.
Apart from that, the 'native from safari'-bit seems to point towards an applescript and/or automator-based solution. Have you tried playing around with that? For instance, in Automator, you could conceivably create a workflow which includes..
'Get Current Webpage from Safari' > 'Get Text from Webpage' > 'New TextEdit Document'
Yang