Hi Tony and welcome to the forum!
Glad to hear that you’re thinking of joining the Royal Enfield rider family. Like you, I recently re-entered the motorcycling fraternity. Also like you, I’m not exactly height/weight proportional so my experiences with my new G5 might be helpful to you.
First of all, the only way that you will know if a Bullet is the right bike for you is to ride one. Definitely take the MSF rider course and get your motorcycle endorsement. You’ll need it to test ride a Bullet.
There are many threads on this forum that go into detail about the character of British single cylinder engines. Long stroke singles may be low on total horsepower but they more than make up for this in torque - at least for me. My G5 practically leaps from stoplights! I have had no problems keeping up with a Harley Davidson Fatboy, Honda Shadow 750 or 1100 in town. Highway riding will likely be a different story but I haven’t fully broken-in my G5 ‘s engine yet. For what it’s worth, I’ve observed from reading this forum for over three years that most Enfield riders really don’t care what other people think. We bought our Bullets because they impress us, not other riders who just don’t get it.
Your style concerns are a litter harder to address. Royal Enfields are relatively small motorcycles. There’s just no getting around it, a big guy can look like a circus bear riding a small bike. Jay Leno recently reviewed the latest G5 Deluxe on his “Jay Leno’s Garage” website. If you haven’t already seen the review you should. There is a link to it on the home page of Classic Motorworks - the host of this forum. Jay Leno is fairly big and tall. To me at least, Jay looked fine on the G5. In my opinion, the G5 and new B5 appear larger than the C5. Maybe its just an optical illusion or perhaps the 19 inch wheels on the G5 and B5 make these bikes look larger than the C5 with its 18 inch hoops. In any case, you should visit your local Royal Enfield dealer and sit on all three bikes. Only you can decide which one is best for you.
Royal Enfields themselves have style, no doubt! You will attract attention riding a Bullet, though if you are an extrovert, possibly not the kind of attention you hope. As my wife would tell you, I am not exactly a GQ kind of guy. When riding, I wear a modern, armored mesh jacket and pants, old rubber sole cowboy boots and a white full face helmet. Nobody I’ve met while riding my Bullet has ever commented on my dorky outfit or portly stature but they sure comment on my gorgeous bike! If you crave attention yourself, you won’t get it riding an Enfield. The Bullet will be the star of the show. Also, if you’re the shy and unassuming type, afraid of strangers with lots of questions then by all means, do not buy a Royal Enfield! I can’t fill up my gas tank without fielding questions from riders and non-riders who want to know where I got my bike, how long it took me to restore it, etc. Bullets are show-stoppers!
Anyway Tony, I hope you test ride a Bullet and let us know what you think. My G5 makes plenty of power for my riding style and she handles like a dream. Once I break her engine in properly, I plan to swap out the stock 17 tooth drive sprocket for the larger 18 tooth sprocket to raise the final gear ratio. She makes more torque at low speed than needed and I’d rather have more top end headroom. Unless you are a speed demon or plan to spend long days droning across the super slab, you’ll probably love riding an Enfield. Get your motorcycle endorsement and give one a try!