Doc Johnson wrote:
Newly here but amateur enthusiast have a Nikon FG ... (
My beloved FG is sitting in its own Domke bag with its SB-15, while the Sunpak 555 is on the shelf next to it.
Your rig is almost identical to mine - fast normal and 70-210 mm.
(I never needed a wide-angle, in the Paleozoic era.)
Nikon D5600 with 18-55mm kit lens, 55-200mm zoom and 35mm f/1.8.
These focal lengths roughly correspond to 28-80mm, 80-300mm (Yes, that is THREE hundred) and 50mm lenses for 35mm film cameras.
You can save a few bucks by going with the D3500 and all you lose is the flippy screen.
The flippy screen eliminates the need to crane my neck for certain shots.
Find an SB-400, AFTER you have tried the built-in flash.
You might not need it.
These new cameras do not need as much flash power as film.
Whatever you do, do NOT use your current flashes.
The trigger voltage is way too high for the new cameras.
For budget, sell any lenses with which you can bear to part and buy new ones.
You will gain auto-focus and lose a LOT of weight!
You can get bigger, heavier, fancier cameras, used or new, but they will not take better pictures.
Personally, weight is a big bugaboo - the less, the better.
The D5600 and D3500 are flyweight cameras that don't require a huge learning curve.
Whatever you wish.
I would just beware of someone trying to upsell you to something you really don't need.