Any port in a storm. If you are looking at zilla brand, your options are numbered I bet the arcadia folk have a hard time finding local reptisuns and vice versa.
Good is relative in this case. T8 is older tech, and has a shorter range & lifespan. It'll work at a shorter range, but I think most folks these days are going with T5s, either Reptisun 5.0 or Arcadia 6% (There are reasons for some to go with higher powered bulbs, but for most w/ a 24 x 24 x 48 enclosure, T5s do an excellent job.)
Unfortunately, a T5 bulb will not fit in a T8 fixture, so if you were thinking about a temporary measure, you'd have to replace the whole shebang anyway.