Back in the days, shipsim sold the Ship Control Unit. It has been discontinued several years ago. There is no dedicated lever for the bow thruster, but you can configure the available buttons. You can still purchase it new on some websites, like here:
http://www.vrinsightshop.com/shop/step1.php?number=24
There was also the Shipdriver. In my opinion it seemed a better option because there were more buttons to configure. There are dedicated switches for bow and stern thrusters. I don't think you can still purchase new, but here is one listed on ebay right now:
https://www.ebay.com/itm/156549214514
Sadly I never had the budget for any of them, so I can't vouch for one or the other.
