Looks like I have a few options:

1. go friction - not my preference but not awful.
2. use an eight speed shifter which may/may not work, again not ideal
3. use and eight speed shifter but switch to an eight speed hub, I would be able to leave the der though? - not sure
4. keep looking for a seven speed shifter - im guessing this would be the ideal so I'll keep looking for now

thanks for the tips