Yeah I modeled mine in CAD too, (we have both solidedge and inventor at work) but ended up making them completely different when I realised that the water outlet and dizzy were completely in the way of number one. I was also slightly suspect as too whether my model actually had the secondaries go straight out between the fire wall, chassis rail, idler arm and bell housing (as you can see from the picture it gets quite tight through there.
These will do for now anyway. I'm going to build up another sr20 with cams and possibly Individual throttle bodies once its up and running and certed so i'll see how these ones go on that motor and go from there. First manifold i've made so not too bad.
I'm also the same as you I can't bear to part with my money to get someone else to do the job, instead i'll spend twice as much buying all the tools required and do it myself!
Where abouts do you work?