Hi - I was away from my bikes for a few years but recently got back on them and am wanting to add an ebike to the herd. I am truly out of room in the garage so I was going to get rid of a couple of bikes to make room, and then realized maybe I should convert one of my existing bikes (all of which I really like for one reason or another) to an e-bike. Given the very high prices of quality ebikes, I figure I don't have to skimp on conversion kits, happy to pay for something top of the line, and still come out ahead vs buying a new bike (and I get to hang onto an existing bike I like).

Wondering if any of you have experience/advice on converting nicer bikes to ebikes would could provide some advice? (A lot of what I see on quick searches online is videos on "how to do a cheap conversion" or "take a really rotten old bike and electrify it."). I am more interested in something that would make me happy I didn't spend $$$ on a top of the line ebike while allowing me to save one of my bikes I really like.

I recently retired, and while I used to be comfortable riding all over town (which is Seattle, which is pretty hilly), I would like an e-bike so I could run errands, visit friends, or just go out for lunch on the other side of town riding civilian clothes. I used to commute, but could take a shower when I got to work; I want something that allows me to comfortably drive 10 to 15 miles for a lunch or errand, and then buzz home (and avoid the temptation to do all this by car). [I would still have a couple of non-electric bikes for out-of-town road riding and mountain biking - this e-bike would be my "retired guy buzzing around town" bike].

After doing a bit of research, I am interested in a mid-hub conversion kit (not a hub kit), and I think it would mechanically work on either of my 2 options:

1. I have a great custom-made steel commuter bike that I used for 22-mile round-trip commuting for several years. Awesome all-weather bike, has also done a little bit of light touring. Triple chainring, drop bars, already has lights, rack and fenders. 32c tires. 3 questions:
(a) should I also consider converting the drop bars to flat bars? I've always ridden drop bar bikes, but lots of things I read say that on an ebike you will find yourself riding upright a lot more because you don't need the aerodynamics of riding on the drops, and you're going faster so you want to sit up and look around.
(b) Would I always want to get away from the triple chainring and simplify the bike with a double or even single chainring?
(c) I see lots of local ebikes here in Seattle with bigger and bigger tires. My commuter has 32c tires; would I find them too small riding a bit faster all the time on (somewhat ragged) city streets?

2. A second candidate to convert is an old Specialized steel mountain bike that I converted into a commuting bike before I got the bike mentioned above. The past several years mainly use for lending to guests, short grocery-getting type rides, etc. I put on butterfly bars, racks, fenders, and street tires. It's not as a high quality bike overall as the one above but I am wondering if it might be a better candidate because (a) it already has flat bars (butterfly bars, which I like a lot) and (b) it has the fatter 26-inch tires which I might find more comfortable zooming across poorly maintained roads. On the downside, it is a heavier bike than the one above, which I know doesn't matter as much on an ebike but does cut battery range a bit on the margin.

Any opinions? Or any guidance on what I might look at/research? Any good guides or forums I should look at?

I know it is a sin to say that I am "thinning the herd" instead of obeying the rule of N+1, but if I don't convert one of these bikes I truly have to get rid of one (or more) to make room.

[It has been several years since I posted on this forum but look forward to your advice]