I have only one question. Where can I buy the sidewinder?
That is a good question. Sadly it would be quite difficult - the parts alone for mine took 11 Bricklink orders and came to around $200USD/£130GBP - though I did use a lot of expensive colours because I'm obviously a masochist.
For someone to do it for you would likely be prohibitively expensive due to the time involved, and it takes sometimes weeks for all the orders to arrive from around the world.
To do it yourself, the basic process is this:
Download Lego Digital Designer (LDD)
Open .LXF file
Recolour all the pieces to the design you want and save
Convert the .LXF file to a Bricklink wanted list file (LDD Manager is a little Win application that can do this)
Upload the wanted list to Bricklink
Check for illegal piece/colour combinations - change design in LDD where necessary, save, convert, upload, check again. Repeat and rinse.
Check for prohibitively expensive / rare pieces - change design as above, etc, repeat and rinse.
Start working out the cheapest way to order the parts from the fewest stores, preferably in a country close to you (US tends to be cheapest but takes a long time to deliver to the UK, and large orders risk getting caught up at customs)
- There are tools in Bricklink that can help
- There is also an application that works it out for you, but it only works for simple orders
Place orders, pay for each one, and wait.
Receive each order and laboriously check it is complete
Contact sellers who missed pieces to arrange resending/refunds. If refunds source the missing pieces somehow - this doesn't happen too much thankfully. Most sellers are very conscientious.
Start building
Realise you have messed up somehow, and need to order pieces you forgot to order or managed to get wrong somehow
Wait for new orders
Recommence building
Suffer crippling self-doubt over lack of social or sex life
Complete build
Eventually get round to photographing it, possibly inveigling a friend who is better at it than you
If doing it yourself, hate the pictures, start researching lighting and backdrop setups, get carried away with DSLRs and lenses... (I skipped this step, as you can tell)
Months later emerge bleary eyed wondering why you ever started.
Congratulations, you are an AFOL*.
Like I said, I'm obviously a masochist.
*Adult Fan Of Lego