I am a new rider (64) and looking to buy a new or used mountain bike and may have electric assist power. I am 6'3" so I need a larger bike. Any suggestions for brand names?
Do you prefer electric, or are you happy with pedal only? There is likely to be a big difference in price.
If you get an electric bike, you need something where spare parts are readily available. With some electric bikes, it is difficult to get parts when they break down. In some cases, parts are expensive.
When I get an electric bike, I will probably get a conversion kit, and put on a regular mountain bike. If something breaks, you should be able to buy more conversion kit parts.
With an electric bike, also consider the height of the handlebars. The cables may not be long enough to raise the handlebars easily. This should be considered by tall riders.
It is probably a good idea to make your first bike not electric. If you want to get one later, it is up to you. A tall rider should probably go for 29 inch wheels. Light weight is good, so you might want an aluminum frame. A steel frame is likely to be less expensive and heavier. You might prefer both front and rear suspension. A bike with front suspension only, is likely to be less expensive.
You could visit bike shops, test ride bikes, and get ideas.
If you come across something second hand, that seems to be good value, check it out.
There are some real nice electric bikes being made in Europe, but they are thousands of dollars. They have bikes with a mid drive motor, combined with a gearbox.
If you come across an old style, large frame, 26 inch mountain bike, they should be good too. They are rare, so you may not come across one. But if you do, check it out.
Are you actually taking it off road or are you only using it on pavement?
If you're only doing pavement, then you would want to swap out the tires for some urban ones.
Such as Pirelli Angel GT.