I doesn't brick your wii. It just removes unauthlorised code (Twrilight hack files). But they already have a TP hack update that runs on 3.3 and as long as you have Homebrew Channel installed you will be fine.
Heres a thread on 3.3
As for your modchip, im not sure how u gonna know what chip u have unless you open up your wii and look at the chip and compare it with the pics on the net.
Hope this helps