i got a cobra 7928 ? (i think there the numbers) for £300, bought it for its cat 1 status and its completely fine, i think a good feature is the amount of beeps it makes once it has been set off, to tell you what has been tampered with.
i also like the fact that it doesnt make a noise when it is set, the interior light comes on aswell when you unlock it which is cool !!
i looked at a clifford concept 300, but got quoted every thing from £350-£400 !!!
i have heard that toad are good as well, but i dont know much about them so i cant comment !