You need to get creative here, as you have mixed criteria for your shipping ...
2 of these are just displays all of the time, while the 3rd is dependant on number of items ...
If you were to copy:
/includes/modules/shipping/flat.php
/includes/languages/english/modules/shipping/flat.php
To the filenames:
flatground.php
flattwoday.php
Then edit the files sets and replace all:
flat with flatground
FLAT with FLATGROUND
flat with flattwoday
FLAT with FLATTWODAY
Those are case sensative and must be done in both the code and language files ...
Then make sure that the plain flat.php is NOT installed ...
Install those two ... you should now see both in checkout ...
The 100+ item shipping is a little trickier ...
Here you also need to make sure that the number of items in the cart is >= 100
You will notice in the flat.php that there is a function to control the $this->enabled based on shipping settings using the a function:
PHP Code:
// disable only when entire cart is free shipping
if (zen_get_shipping_enabled($this->code)) {
$this->enabled = ((MODULE_SHIPPING_FLAT_STATUS == 'True') ? true : false);
}
If you were to copy flat.php to flat100.php and do the global replaces for flat to flat100 and FLAT to FLAT100 ... you would then need to make your own function to test how many items are in the cart, and if $_SESSION['cart']->count_contents() >=100 then you would allow this to show by having a function test that value and return true when allowed and return false when not allowed ...
Look at how the current function is written for the catalog and admin for:
function zen_get_shipping_enabled
You can find where that function is located using the Tools ... Developer's Tool Kit ... and searching in the bottom input box for:
function zen_get_shipping_enabled
And then, select Catalog/Admin from the dropdown and click search ...