Answered How to find products similar to current product? F/U: And sort them by name?

I didn't notice the calculations.

I would do something like this rather than array_merge(), it should be slightly faster and I think the code is a little easier to follow:

$fields = $family->toArray();
$imgName = $family->get('name');
$fields['nwN'] = 'Name: ' . $imgName;
$fields['imgLink'] = 'assets/media/jpgs/' . $imgName . '.jpg';
$output .= $modx->getChunk('showProductFam', $fields);

For sorting:

$c = $modx->newQuery('BbProducts');
$c->where(array('fam' => (int) $famId));
$c->sortby('name', 'ASC');
$families = $modx->getCollection('BbProducts', $c);

$famId = $_GET['famCode'];

$c = $modx->newQuery('BbProducts');
$c->where(array('fam' => (int) $famId));
$c->sortby('name', 'ASC');

$families = $modx->getCollection('BbProducts', $c);
foreach($families as $family) {
    $fields = $family->toArray();
    $imgName = $family->get('name');
    $fields['nwN'] = 'Name: ' . $imgName;
    
    $fields['noImage'] ='assets/media/jpgs/noimage-s.jpg';
    $imgName = $family->get('name');
    $fields['imgLink'] = 'assets/media/jpgs/' . $imgName . '.jpg';
    if(!file_exists($fields['imgLink'])){
      $fields['imgLink'] = $fields['noImage'];
    }

    $output .= $modx->getChunk('showProductFam', $fields);
}

Looks great.

No need to do this twice, though:

 $imgName = $family->get('name');

Also, If there's no '+noImage' placeholder in the Tpl chunk, this will be more efficient (moves setting the value for noImage outside the loop, since it never changes; and avoids several associative array references which are much slower than variable references):

$noImage = 'assets/media/jpgs/noimage-s.jpg';

foreach($families as $family) {
    $fields = $family->toArray();
    $imgName = $family->get('name');
    $fields['nwN'] = 'Name: ' . $imgName;
    $temp = 'assets/media/jpgs/' . $imgName . '.jpg';
    $fields['imgLink'] = file_exists($temp) ? $temp : $noImage;
    $output .= $modx->getChunk('showProductFam', $fields);
}