This whole thread is pointless.
You are saying that you want to buy a sportrider to then double the bhp on. Even if you got a good deal on the sportrider, the extra work will surely cancel out the increased cost of the cupra over the sportrider. Even if you took it to 160 bhp, the cupra's insurance would be lower as a standard car than a modified sportrider.
This is of course unless you are intending not to declare the mods (as you have insinuated), in which case starting with a sportrider and turning into a tuned cupra will keep your insurance costs down and still maximise power. People have said 'why don't you just cancel your insurance' - well this is easily answered, because the OP doesn't want hassle from the police ANPR camera's - he is much less likely to have an issue with undeclared mods than no insurance at all, until the point if/when push comes to shove and he has an accident/is pulled etc.
You complain about fuel and insurance prices, but its people like you who drive prices up - someone has to pay for the fuel that people like you steal, and someone has to pay for accidents caused by uninsured drivers - and its us, the honest motorists.
Personally, I don't see why any of you are posting constructive replies to someone who has pretty much admitted that he will not declare these mods. I wonder how you will feel when you have to post up an 'I've been hit by an uninsured driver' thread. I don't see why we should condone this behaviour by offering
help and support.
I'd prefer to see this thread go to the scrapyard. I just hope the OP's current insurance company see it first.
Rant: over.