Hi there Sean,
I think that perhaps(unless I'm misunderstanding your problem), you're over-thinking your dilemma.
Your HTML form doesn't have to contain any PHP. It of course can, if you need some dynamically generated content in the form. The php is pretty much the star of the show for the processing of the form, but for the form itself, it's completely optional.
Your select box can be written as any other select box would, then you receive the value on the other end:
$value = $_POST['value'];
Then of course, you can handle assigning an attribute to the selection any way you wish, and at any time along the processing stage:
if($value = '1'){
//do this:
$value_attribute = 'Dandy Warhol winter socks';
}
The only thing that requires a bit of thinking are checkboxes, as they aren't set unless they're used, so you handle them via an ISSET/!ISSET method, but the rest of the form processing is pretty straight forward.
Again, if I'm misunderstanding your problem, I'm sorry for wasting the page space.
🙂
json