You're best off staying with Jaguar. Panther and Tiger are really a bit much. Panther will want 256mb really.. So you could up it and try, but Jaguar is really as far as you should go, otherwise you're just going to kill it.
I run Panther on a Powerbook with roughly the same specs and it works although it takes a while to start up and get going. The advantage of running Panther is a lot more applications become available to you, as most seem to require 10.3.9 minimum nowadays.