Just buy a very common GM 3 bar...although most of those are chinese now too.

I've only ever seen one cheap Marelli copy 3 bar...it was a mile of correct spec.

But if you're using an aftermarket ecu, none of that matters as you'd be calibrating it correctly anyway

For proper quality, KA sensors etc sell nice ones. MAP sensor is important...I'd pay the extra for known quality.

http://www.jti.uk.com/?product_cat=map-sensors