I think you're already getting the hint
However, for what it's worth again, my first car was a 1.2 Vauxhall Nova. Worth about £3k. It cost me £1500 to insure it Fully Comp at the age of 18. That stung.
MANY years later, I went to pick up my Subaru Impreza. A young kid turned up with his parents. The salesman wheeled out a brand new P1 Impreza (circa £31k)......
"Happy (17th) Birthday, Son"
Took the sheen off my purchase that day, I can tell you!!
The point being that I went back about a fortnight later to sort something out - the salesman was laughing about *that* sale...... the kid was being charged £5k
3rd party fire and theft......
Get yourself something smaller (potentially with free insurance to build up your NCB) then come back - you'd probably quite easily get something like an R20 at decent money then
)
Best of luck either way
Dan