Hi and sorry that I didn't explain the whole performance mod thing very well, I'll try again.

Performance parts for Chinese bikes (or at least bikes with our engine) almost always have to be imported from china, these parts can be found on taobao.com which is the Chinese equivalent of eBay. Most Taobao sellers do not accept payments from foreign credit cards and banks so you need to use a Taobao agent to order the items for you; they will charge you a small fee which is usually a minimum of £5. I use taobaonow as give you 40% off international shipping. Remember that shipping stuff from China to the UK is very expensive; the shipping costs usually exceed the cost of the items.

Our engine is just about identical to the Suzuki GS125 and GN125 engines and has similarities to the EN125 engine, As such it is best to search for GS125 or GN125 parts rather than searching for parts specific to your model of bike. I have found it best to use Google Chrome to search for stuff on Taobao as it automatically translates the page, when searching for items you will need to translate the search in to Chinese (which can be very hit and miss) and put GS125 on the end.

Links:
As far as I know this is the biggest bore kit available (and perhaps the biggest possible too)
http://item.taobao.com/item.htm?spm=...id=14901325189

I would imagine that this is the best performance CDI as it has 4 modes
http://item.taobao.com/item.htm?id=9153886492

I spent hours looking for a performance camshaft specifically for a GS125 and I could only find this which is for the EN125, it looks the same but I don't know how it will perform
http://item.taobao.com/item.htm?id=17729324299

6th gear kit
http://item.taobao.com/item.htm?spm=...&id=9576478120

As for the crankshaft I haven't read too much in to it. I think you can just put the crankshaft from the 200cc version of our engine in the 125cc version.
http://item.taobao.com/item.htm?spm=...id=14610333239