Whats wrong with the cover thats on it? Looks pretty tidy to me, nice job.
The chrome pump reservoir is very nice, but wow its pricey too.. and remember it then becomes the shiniest thing in the engine bay, which means you will then need more chrome to even it up.... its an expensive trap
Honestly, if it were me, I'd be very happy with just the new plastic reservoirs and leave it at that. Red goes with green mate, no worries.. but I think it looks better than green under the bonnet. If you really want green though, just spray the red bits green and leave it at that. You could maybe then use black leads instead.
It looks very good the way it is mate. Clean and tidy, obviously an engine bay that is cared for. Thats what you want at this point. Until there is more to show off, like an intercooler
then much more than that is probably a waste. Just my own taste, thats all
Less is more.
I'd be avoiding painting things like leads. It wont work well, and it will look just plain tacky IMO.