I have heard lava rock style shielding is said to be a good thing for where you have the gold reflective.
More shielding the better and any fresh air ducting to there will be ideal. Like brake ducting. Or like the caldina ducts fresh air to the alternator shroud - that kinda concept may help, however the fans should see the best improvement. Fan shrouds were available from a James in Ipswich, unsure if he had any left.
Looks good and coming together :)