3speed

Retro Grouch 

I'd vote for neither.

The older bike is likely to have worn pivots, bushings or seals and many suspension manufacturers don't even source parts for products more than a few years old.

A new bike is going to use part of your limited budget for suspension components that really don't do much.

3speed

HerrKaLeun

if it was good 15 years ago, you should have done that project 15 years ago
full suspension, or not, any bike from a box store, are not good and not worth for any upgrade, especially not an expensive e-upgrade. Period.

If you don't have the budget to do it right (good bike, and good e-bike drivetrain), just scramble your money and get a good human-powered bike.

3speed

Rollfast

I put a new aftermarket springer from ebay on Rosa my cantilevered 60s Rollfast and that really made a difference, other than getting over feeling like you have a flat maybe now and then. Like a Buick with Dynaride

Ironfish653

I'd vote to skip the suspension, as well, and look for a 27.5+ hardtail. E-bike or not, rear suspension isn't going to do much for you on the street, unless you're the kind of guy who has to ride through every pothole because he can't ride around them. Any of those ~3"+ tires will give you enough volume to take the shock of poor / scabby pavement, without all the fitment issues that come with adding a motor/engine drive on to a rear suspension. I'll assume you know how to shift your weight to your feet and 'ride light'

One of the reasons i've stayed with an MTB-based commuter (26" hardtail) is that a 1.95" tire can comfortably shrug off most paved hazards without giving up much speed over something like a 700x40.

veganbikes

I would vote no to everything! If you want an e-bike buy an e-bike if you want a crappy bike that you slap crappy stuff onto to make into a really bad hybrid thing that isn't a good bike or good e-bike then maybe don't do it.

A properly designed e-bike with a mid drive motor from say Bosch, Brose or Shimano with wider tires and maybe a suspension fork upfront will do a fine job and also will have warranties and be easily serviced at your local shop and is less likely to fail or have issues. Those homebrew kits from China are a nightmare to deal with and frequently have more problems then they are worth. When you bolt a big heavy wheel on the front or back you tend to break a lot of spokes (even on the higher quality ones) and when you bolt a motor to your bottom bracket it tend to come loose often and can strip threads or crack BB shells and are just so unreliable.

Specialized Vado 2.0 is pretty cheap or you can go up and get a nicer one with better components and the 28mph motor. It has suspension fork at the front and pretty nice wide tires and is a great bike for the city. Me personally I would go and went with the Raleigh Redux IE which I am currently replacing all the bike components on it for nicer stuff (not because anything was bad but I am a tinkerer and wanted to "pimp my ride" like "x to tha z exhibit") however if you needed suspension you would have to swap out the fork, I went with a carbon fork (from Fyxation) simply because I wanted to cut weight. I also added a Kinekt Seatpost which is a "suspension" seatpost which could be a good addition to any e-bike as it will do an excellent job soaking up the city streets. I tried one on a bike with wider tires but NO Suspension and intentionally hit rough pavement and potholes (which I generally try to avoid) and it really did an excellent job without the need for heavier suspension forks or worse trying to go full sus in the city.

Also those Wally-Mart specials have almost no travel, I think the new Specialized Future Shock headsets have more travel then the stuff from Wally Mart and those weren't designed for MTB or much travel anyway.