You can't use wideband LNB with any E2 receiver directly. If they fitted a Hybrid LNB, then you can use the legacy/universal ports.
You can use a universal/normal/ordinary LNB with FBC tuners. Unicable LNB is not a must.
With the traditional LNB and FBC, you can record more channels than a regular tuner. Obviously depends on which quadrant you are accessing.
However, Unicable LNB does allow you to configure the 8 demodulators separately. If you want to make the most of the FBC tuners, then best to get a unicable LNB, dish adapter and splitters.
The MTSIF terrestrial tuner is just like the normal twin terrestrial tuner with regards to recording. The connections to motherboard are different. I think they are not hybrid.( Cable/Terrestrial)