hi all what size wheels fit best and look good under wood and picket wheel arches?

Everything fits under them. Take your pick except for 13x7s.

so any 13x6 any offset

Most 13 x 6s do, some don't.
What sort of wheels you thinking of specifically?

like minilites id like to go 13 inch but i dont know what offset and how wide photos would be good

or ultralites

Performance 13x6s come in 23mm positive, they're about the limit.
Ultralites are 10mm positive, can't comment on them. Seen it done, but the car might have had drums.
Minilites go out to 28mm positive, you'd be fine there, but not sure what the normal offset they do for minis is.

ohk im running discs on the front