actually tipper is quite well internationally known, was originally signed to Sony, then went to Fuel where he released most of his work to date and has since released on Delicatessen, Colony, MyUtopia (and others im sure).
Freeland has released on a bunch of dance labels to, and runs Marine Parade, a breaks label out of the UK.
tipper and freeland are on about the same level in my opinion... if you are counting album sales and international gigs.
sandra collins would probably be the 'biggest', but thats because she plays more popular music. trance. i dont think she produces though.
lastly, not that it truely matters... (heheh)
lorin was playing in New Zealand and Australia last time i was down there, and i know he plays internationally rather often... same with Adam Ohana, whose current moniker, ant-en-nae, is just that, his most current moniker... having released on german and british labels.