Ironing out issues in online shop

I've been creating a website for a friend which contains a small shop online section. Initially this seemed to be easy enough to do, however I need some help making sure everything runs smoothly as there have been a few issues that keep popping up which I can't find totally satisfactory answer for.

The company is a florists and so the way the shop needs to work is that customers can select the type of bunch they want and then have it sent to a specific post code in london. In many ways the shop online section is probably more like a delivery service as each different postcode has a specific delivery price.

I've got what I need up and running to an extent

the example is here;

http://www.harperandtoms.co.uk/HTML/ShopOnline.html

I've used paypal and ejunkie shopping cart but it still seems somewhat clunky and I can't completely customise the checkout page - ideally I'd like to be able to input a delivery address, personalised message, two telephone numbers (for the sender and the reciever) and have it all sent through to the shop's email.

I would love to get the shop online page working in a similar way to this site;

http://www.philloflowers.com/checkout

but I'm not sure how much work is required there.

Also the way I got around the delivery postcode was by treating each delivery postcode as a separate item. I think this works okay but again if there were a more effectve way of doing this that could be great.

It's nearly there ( I think) but there are a few issues that I just need someone with more knowledge and experince in ecommerce to point me in the right direction or potentially show me a better way of doing this. Ideally someone who knows how to customise the paypal checkout page (if this can be done) and is very strong in scripting and if you have created a shop onbline before that would be incredibly useful.

The main issue is I can get everything I need in Dreamweaver working but the shop online bit has a few specific requirements that are more difficult to get right with online widgets and shopping carts alone.

I can either do it remotely via skype or if you are close by (north london) then it may well be easier for you to come and meet and I can hand over my computer and let you have a look! I'm thinking that it should only be a day's work but please let me know any other questions and in your bid let me know if you think what you think is realistic and what isn't.

I'm meeting with the client this friday and will take any questions from them so I'm ideally looking to sort this out one day next week.

thank you!