I too hate Tomahawks. Ghastly piece of junk. Did the 1st 20hrs of my PPL in them before walking out due to spotting some awful maintenance issues under the bonnet. They were made for only about 2 years, around 1980 (too many people got killed in them) and all seem to be in a poor condition, They leak during the rain (those I used to fly had puddles on the floor) and stink like a public phone box, they leak into the tanks (I once drained out about five test beakers before any fuel started to come out, after some heavy rain), the elevator trim is a spring pushing against the yoke (in effect) and doesn't work properly... it is too lively to fly from A to B which is why instructors like them (they have an "interesting" stall behaviour where they suddenly drop a wing and since the ailerons are ineffective you have to be quick on the rudder otherwise you plummet sideways very fast. I used to enjoy doing the stalls...
I would train in the plane which you want to rent afterwards. Anything else is a waste of money - probably a waste of 20 hours' training, counting from zero not to the point of getting a PPL but to the point of getting confident to go somewhere.