Hey Korvus,
Just wanted to chime in with my experiences and situation and see if it's any use to you in your e-bike quest. I have a perfectly good car but wanted to lower my carbon footprint as well as stop worrying about traffic for my commute, which is 22 miles one-way with a couple long, gradual hills. I was initially set on doing a conversion of a BikesDirect road/cyclocross bike but ended up going with a Juiced Riders ODK U500. Here are a few points that helped me convince the wife this was worth while - 1. I got rid of a motorcycle and replaced it with the ODK which is in theory safer, 2. The ODK with the 32ah battery can do my full commute round trip w/o recharging with very little pedaling effort, so I can do it even if I'm totally exhausted or not in the mood to exercise; this theory applies to all other trips and makes us more likely to use it 3. The frame geometry means my wife can ride it as well, which is a HUGE plus and makes the bike much more valuable to us as a couple, 4. It can carry enough cargo such that I can do the grocery shopping (and general shopping) with it. My wife can also use it for shopping if I'm not using it. 5. It comes with a 2 year warranty on everything- something a DIY setup generally lacks, 6. It's stress-tested and waterproofed - another thing a DIY setup can't ensure, 7. You actually get customer service so it feels like you're not doing it all on your own if you run into problems.
I've owned the bike for 11 days and have put 226 miles on it and haven't had any major issues. It is very heavy and a bit cumbersome when moving it indoors so if that's an issue you could look at the CrossCurrent offering that Juiced has that's sportier and lighter I really like Juiced because they have awesome customer support (founder and CEO Tora will reply to email questions the same day) and they only do two models, so they're very focused on making those the best possible value and success.
Just my .02!