Firstly, I have experience only of combined TV/TI systems, not of the better quality ENG style TV systems.
LEO-400:- early system but fairly reliable, go for the 3-CCD TV not the single CCD. THV-1000 TI generally reliable; laptop controller rather less ergonomic but better than those with a pistol grip type control.
LEO-2:- not much experience of this but good TV zoom [54x as opposed to 32x] and slightly better TI; good laptop controller.
Ultraforce [latest]:- good TV zoom; TI has advanced technology but is as a consequence almost too complicated. If you are using it is the police role the wide lens is a little too wide for target acquisition at heights that allow the [excellent] narrow lens to be used. Ongoing problems with TV focus and over-complexity of TI image setup.
All the systems are of the 60-70kg overall weight including pod, wiring and contol boxes. the later systems do have slightly better stabilisation but are really quite expensive. A maintenance contract with any of these is highly recommended. The cheap and cheerful smaller versions are however reflective of how much you pay.
Wescam, anecdotally is a good system but I believe here in the UK there have been problems with product support.
PM me if you want a longer discussion.