Cant comment on those gauges but have you thought about Nomad ones?

I paid £80 for the two gauges, 2 senders and 2 adaptors to fit them. I dont know how accurate they are but even if they are to the nearest few psi etc I took the view it would still be better than nothing. It also retains the normal warning light on the dash.

(PS - would have loved the likes of the Defi ones but like you, had already spend more than I could afford on other stuff for the car )