Jobo tanks and tank extensions (extension tube needed with each section) are the best to avoid leakage.
You can keep using your Paterson tank system if you learn Figure-8 agitation. It eliminates leaks and produces perfectly-developed films.
Figure-8 Agitation
Some developing tanks cannot be inverted without leaking. In that case you can use Figure-8 agitation. This consists of keeping the tank upright at all times and moving the tank in a figure-8 pattern from right to left. The tank can be held by your hands and moved through the air, or you can slide the tank on a smooth countertop or tabletop.
We agitate by moving the tank vigorously in a figure-8 (long dimension from left to right) from 300mm to 400mm from right to left. The 300mm-400mm dimension is simply a starting point and can be modified as you see fit. The tank should make one complete figure-8 in 1 to 2 seconds. This is vigorous—as it must be—interspaced with rest periods (which are just as important).
I sometimes use a variation I refer to as “Double Figure-8”. This is two complete anticlockwise circles on the right joined to two complete clockwise circles on the left, and so forth in a continuous motion.
Another variation I’ve used recently is even easier. Simply orbit the tank anticlockwise in a roughly 200mm-diameter circle for 2 quick orbits, stop abruptly, and do 2 more orbits in clockwise direction, and so forth. The tank does not rotate on its axis and stays in a horizontal plane. All that's really needed is to strip the thin layer of depleted developer from the emulsion and remix all the developer into a uniform solution without concentrated bromide in contact with the emulsion (bromide is released from the emulsion during development).
This gives perfect results with any roll-film tank, those that leak when inverted and those that don’t. The agitation is adequate for uniform development and generates no developer-displacing foam. I’ve used these alternate agitation modes since 1987 with good results after spoiling films with conventional inversion agitation.