4 different shipping options/dated delivery charges WooCommerce

Hi support, I kno this isn't a WPMUDEV plugin, but was hoping someone could help as I've been searching around and can't find how to do this!

I'm almost ready to launch on my new site: http://www(dot)flowerstudioshop.co.uk.gridhosted.co.uk/ - just having some teething problems on the woocommerce checkout/delivery options.

I basically want to have four shipping options:

1) FREE standard delivery - (This is the default option if based in the UK - WORKING FINE)
2) Dated Delivery - for a cost of £5.95 your flowers will be sent by 24hr courier on your specified date (I have a date picker on the checkout screen via this extension: terrytsang.com/shop/shop/woocommerce-custom-checkout-options/ - but it doesn't force the shipping to change to £5.95)
3) Saturday Delivery - for an extra £10.00 your flowers can be delivered on a Saturday before 1:00pm (I want to be able to set this up too, but not sure how to do this)
4) International Delivery (WORKING FINE)

The biggest problem is going to be getting date selected delivery to charge £5.95 and delivery on a Saturday to charge £15.95.

What's the point in having a date picker on the plugin mentioned above if you can't affect the delivery charges?!

Any help/suggestion much appreciated!