There are plenty of choices.
53-56 will be in your range depending. I prefer 55 or 56
Raw will often be cheaper, but is open to various scams- trimming/reprints/photoshop tricks etc.
The best choice in my mind when dealing with card issues that you are not familiar with is to go with grading companies (warning: opinions coming take them for what they are worth):
PSA- great for investors - the higher the grade the better - more abundant in your date range sturdy case
SGC - visually appealing case - often mistakenly associated with OLD cards (Pre 1940) so not much in your current range
Beckett - not many out there - large case often the best bargain
That being said the grading companies have warts too: inconsistent grading/slabs can be tampered with/ they have mistakenly graded reprints.
Just a matter of piece of mind to go with graders.
But tell more about the boy- what does he collect already? Does he collect graded cards now? Does he have a preference in company?
I always say buy the card not the grade...
A nice PSA 1 1953
A PSA 4 1955
An SGC 60 1956
or outside the box:
1955 Golden Stamp PSA 8
Exhibits PSA 4.5
Either way just thinking this way is pretty cool- good luck and hope you update us with what you got!