Gas/electric Hybrid bike?

So, I'm thinking, when I switch up the bike, I wanna go with a front electric motor, something with plenty of power (and ungoverned), say capable of 25-30mph, though I wont complain if its faster. range isn't an issue, I need it to have regenerative braking (or something that can charge while rolling) so I can start with the electric until it runs out of juice, then run the gas motor, then go back to the electric motor when it's either charged or I run out of gas (hence why I want one that can charge while rolling, or maybe even trickle charge it with the gas motor). Of course the gas motor will be capable of much higher speeds (most likely anyway), but I want the electric to maximise range, and for short/pleasure cruising, or even assisting the gas up steep hills or in case something happens with the gas motor.

I live in canada though and cant seem to find much. I expect to pay around $500 for the hub, battery and controller. Regenerative braking would be a plus, and a small rack mounted battery would be good as well. If at all possible, a left-side thumb throttle or twist throttle would be ideal, or if one exists, a brake/thumb throttle combo on the right so I can use both throttles easily. Any assistance getting this accomplished would be greatly appreciated, just, like I said, i'm in canada so they either have to be from here, or ship to here. I'm willing to go separate parts because my wants from a kit arent exactly ideal.

so I should go with a smart pie? decent power? good for short commutes and emergency running right? are they able to go on the front wheel? If so then that'd be perfect (I'm pretty sure they have regenerative braking). Now all I need is a small battery that would fit either under or on the rear rack, or something. A 20 mile range would be more than adequate, my ride to work is only 3 or 4 miles. I learned they do have left side thumb AND twist throttles.

awesome, that sounds perfect, any idea where I can get one for relatively cheap in canada?

EDIT: are they just simple hubs that you string up with spokes to any size wheel? For example, I wanna do a 29'er.

yeah I was lookin at that site, a tad pricey, do they come with the battery? I know they come with a throttle, still, at $350 it gives me a bit of play room for a battery. You think that'd be a good idea? Front electric drive, and rear gas drive? I think it'd be good for emergencies and range extension.