"Please find attached the details." is incorrect, you need to use a couple of commas if you want it to make sense, so; "Please find, attached, the details.".
"Please find the attached details." sounds the most professional, this is your best option.
"Please find attached details.", as "Please find attached the details." is incorrect, but you need to add two commas AND the word "the" for it to be a full sentence; "Please find, attached, the details.".