Hi Titus! Great questions here... I used to work with a guy named Nick who just about fits your profile. Tall guy but fit and muscular, he weighed in the same range and I was uncertain how my ebike (the Neo Jumper) would respond to his weight and size. After work one day he came down to the parking garage with me and I just turned it over to him and told him to cruise up the ramps to see. I have to admit, it was a bit unsettling because I paid thousands of dollars for the bike out of my own pocket and used it every day to get to work. As it turned out, the bike did struggle a bit more going up the hills in throttle mode but it still made it and when he started pedaling (and using pedal assist mode) it really picked up. He was very impressed and thoroughly enjoyed the bike. After this experience I did some investigating and it turns out geared hub motors have a bunch of different ratings and peak outputs and the battery voltage comes into play etc. BH (makers of Easy Motion) have designed and tested their battery, controller and motors to integrate well and they do seem to offer more power and speed than a traditional 350 watt 36 volt combination (which I'd call average in terms of power). I would regularly hit 26 mph in pedal assist mode and never felt like the bike was struggling when I rode (though I'm 140lbs).
So, I've provided some qualitative feedback on power but the other part of your question was about frame size... Easy Motion actually offers several of their ebikes in larger sizes that could work quite well for you. Of the two you mentioned, the Neo Street comes in size medium and Large. I've attached the chart from their website below (and it's a bit confusing to me actually). It came from this page
. The Neo Cross is the most popular review from Easy Motion on EBR so worst case you could probably find a buyer if it didn't work out
I believe the Falcon 350 only comes in medium and while it's less well known than the BH bikes I've been in touch with the founder and he seems to offer good support. Since you're already trying to make the size/weight thing work I'd stick to Easy Motion or... consider getting a Pedego. They make one called the Interceptor
that has a large 500 watt geared rear hub motor and 48 volt pack (but only offers throttle mode) and another one that might be perfect for you called the City Commuter
that runs on the same specs but offers pedal assist! Note that it's pedalec vs. torque sensing which Easy Motion uses on their bikes. I owned and rode one of the first City Commuter bikes they launched in 2012 to and from work for a year and it worked excellently. Their frame sizes are pretty large and I actually opted to get the step-through (smaller frame) as a result even though I'm 5'9" and would usually prefer the high-step look.
More anecdotal thoughts here but the co-founders of Pedego are both larger guys, one is tall like you and and the other is just boxy. I bet they weigh as much as you and I know they get around just fine and have really designed their bikes to be capable haulers and hill climbers. The origin story for Pedego actually comes from one of them trying to get up this hill up to his house every day and getting frustrated with it. Their ebikes solved that... His name is Don and you can see a post from him right here
(and see a picture of him in the user icon).
Given your budget, interest in pedal assist, physical constraints and desire to get something that will last and provide a great riding experience I'd say the City Commuter, Neo Cross or IZIP E3 Dash
would be great choices (though the Dash isn't quite out yet and I'm not sure if it comes in a larger frame size). Feel free to expand your question, reach out on Don's Pedego thread or go in a different direction. I'll chime in again to try and help you out!