States Plates will make you a set in alumin(i)um, to your design. They replicate those used in the USA. I think I'm correct in saying the front ones are legal in UK, but the rears are for 'show use' only. (My C6 passes the MOT with a US-sized effort on front, with a 'proper' UK plate on back, which I replace with the US-style item as soon as I get back from the testing station).
States Plates will colour them correctly (white front, yellow rear).
As well as the actual licence number, States Plates will incorporate other script (in smaller digits) above and below the main number
(e.g. '2007 C6'; Chevy 'Bowtie' stamp; '400/400'). That last is the HP/Torque rating for an LS2.
All easily done on the internet.
They're in France, if I recall correctly; delivery will be about 2 weeks from order.
I hope this message doesn't fall foul of 'promotional' guidelines; I write purely to onpass info. and have no connection with States Plates apart from being a customer.
I have had C5’s before where they had plates that fit the front recess rectangular in shape, but do not know here they came from and want one for the rear. Have seen some people running small front plates which I know are not legal but look cleaner
I got mine online from platesdirect.com. I specified the 305mm x 152mm size, which is as close to make no difference to the 12"x6" US plate size. They were a good price, quick delivery and the web ordering system worked well. For your requirement you can specify different sizes for front & back, so you can choose whatever size you like - I see they do a 9" x 3" size which is small !!