[Frekkel]

those are forged pistons

what you want is this original part: LFL000800 (but they are in backorder at the moment) and cost +230€ for one conrod and piston. and I guess you also going to change the bearings?

that's near 1000€ for 4. (but then off course you say you only need 1 set)
forged pistons and forged conrods aren't that much more. So while the engine is open you can change the internals. Are you sure the others are still fine?? did you measured them up?
unless you want to keep things standard.

 

[Frekkel]

- look at the sponsors of the site, contact them and they can send you the parts, But if they're not available it can take a while

-If you buy from xpower, ptp,... you get 4 pistons, 4 conrods,...
If you measure your bearings and they are in tollerance, have no marks,... you can re-use them in theory. But for the price that it cost I would take newones. You can also buy uprated. You can go as far as you want. Some may say you also need a steel cranck, others say just stay with standard...

normally they have those parts in stock.

I think you need to know for yourself if you want a standard car or if you know you want some more power. If you think 157 bhp is enough and you just use the car to go to work. then forged pistons, conrods,... would be silly money. If you already have some breading mods and you want to go further then this is a chance to uprate the "weakest" part of the engine. And then it would be stupid not to do it.