I've seen brand new TW heads for sale anywhere from 750-900 on CL in the box. IMO, if you are going to spend $800 for a set of cast iron e7's just to look stock, stock out of the box gt40;s flow about 195cfm/140cfm. You can get them all day long out of the JY for less than $100. Send them to a machine shop for $100 or so to get cleaned up and checked. another $125 for upgraded springs and you have a decent set of heads for less than $400, 1/2 the cost of the cast iron ported e 7's. Combine that with a good cam and like you said, are you going to notice the 20 cfm less for $400 more money. You could use that for the cam, throttle body, etc. Then he can always save up for a good set of alum heads when he is ready to step up in performance.
I have a 90 vert and did just that, took the top end off a 96 explorer- intake, heads, and did the spring upgrade, added a 70mm TB, 95 gt MAF, FMS shorty headers, H pipe,
BBK CAI, everything but the springs I bought used and am very happy with the results. Removed the smog pump and hoses and will be adding U/D pulleys and a Taurus fan I just bought used. Then 3.73's , a silver fox valve body, and B&M Hammer also bought used. It's not the fastest but so far it is a vast improvement over the bone stock car I bought 6 months ago. When I feel the urge for the next level, I'll throw an S trim on it and swap out the heads, intake, injectors and MAF, and go with a TFI cam from Ed. No sense buying two custom cams and the stocker is fine for now.