I own one of the hybrid Sirrus bikes as well. I suppose it would be an excellent choice for a conversion but like others said the bike is equipped with V-brakes. Newer models come with disc brakes so you might at least be able to by a new fork that would give you the option to covert one wheel to disc.

Ebike ( road versions...ie..with 700 x 35C wheels ) will just have a whole different feel / ride characteristics than a standard bike. If I had to do it over again I think I'd like a road version ebike with a front shock. I put a Thudbuster seat post on my ebike and it made a big difference. The front of the ebike though picks up way more vibration and hits than a standard bike.. On my ebike that's probably because the heavy battery is mounted to the down tube. So far it's not been a major issue but I might consider a shock stem if it really starts to bother me. ( I have a bad neck not to mention problems with my shoulders so the less vibration to my arms the better....I'm 64 )