Hands down the Pentel RSVP ballpoint pen
I wish more businesses would invest the $2 it takes to utilize these pens. It’s basically going from: “Hey, Michelangelo, we’ve got this large block of marble, and a hammer. Make us a masterpiece!” to "Mr Buonarroti, here are all of the tools you’ll need to write tiny text on tiny pieces of marble
I had the same issues years before I bought my Canon 7D. AFAIK there isn’t a pcpartpicker.com for photography gear, but I spent many hours reading the forum posts and reviews on DP Review.
The main takeaway I got from them was to spend on lenses as they will stay with you through multiple camera bodies.
Also if you go the Canon route, they used to (and maybe still do) have a program where you get a credit for trading in a Canon camera. It did not need to be working. I bought a dead canon from ebay (~$20), punched in the serial, and I think they gave me over $100 discount/credit towards a body
If you’re going to buy used lenses, make sure you test them thoroughly, a used lens is like a used HDD, you have no idea what the last person did to it. Also, if buying online, make sure you look at the return policy, a lot of places will make you pay the shipping for returns. HTH