Thank you all for the encouraging words. So first off, a spreadsheet of the parts. Item Number, Quantity, Description, cost, Visible, Alternative parts etc etc
I know some folk who great skills have these posh databases etc but this is the best my lowly GCSEs can manage :)
I've given Brickficiency. a quick blast and I think it should prove useful. From the experience of others I'm going to put in a fair bit of planning before I actually start to purchase parts. Someone very kindly posted a list of the parts which are not visible which might help reduce the costs. I'll update the spreadsheet to show the non-visible parts and where cost is saved update the alternative parts used list.
I'm unlikely to go for big mods in the form of interiors although they look fantastic. However, the one mod I really like is the engines like this - hope the creator is ok for me to share. What I might do is create a seperate page on the spreadsheet to provide parts lists for any mods carried out along the way.
Once the above is lit it looks superb IMHO. The plan here would be to substitute the OE parts for the parts required for the mod at the purchase phase to save buying parts that will ultimately be unused. However, one thing that I'm not sure about is how is the curve achieved? I don't quite get how the parts stay together without creating a ridged line.
Once I've tweaked the parts list my only real question is where to start. I'm thinking to set myself a budget for the first round of purchases, say £100, and buy in order on the spreadsheet and keep to as few shops as possible to keep postage costs to a minimum. I'm also thinking should I go for the buy a brick option via Lego direct or stick with BL. Try both and see which provides the most bits for the least cost is the obvious answer.
I'll update once I've got the sheet near to what parts I'm actually going to get and details of the first order.
Thanks for reading :)