If I were you, I'd get a temp controller, a fan and temp sensor of your choice and make a stoker fan for that thing.
That will not only take care of the thermometer problem but the cooking temp too. It's the only was to go with a charcoal or wood fueled smoker. It makes life so much easier and takes all the fuss out of it.
You can buy them made up already but they cost way more than they are worth IMHO. If you're at all handy, you can whip one up for less than a hundred bucks that inclues the fan, the digital temp controller, the temp sensor and the little bit of sheet metal that you can bank out yourself in your own garage or even an apartment for that matter.