It really depends on what features you want.....
I Run AU 845 2611, NZ 850 2781 and UK 850 2781 with ALG and TTS on 9.004 also on 9026 in X30 and X40 emulation. 9026 will run in X50 mode with handsfree not being functional.
The choice is yours as the 720 is probably the most adaptable TT. It will virtually run any navcore including Truck versions.
I would first patch my existing navcore 8.351. If it is not yet 8.351, have TomtomHome upgrade it to 8.351 and then patch it with easyusetools or ydGpatch.
Then back it up somewhere safe and try 9.051 SE. This one runs great on my 920, including TMC. However, do not run x50 mode but x40 instead or TMC will not work.