This is a different head (my current race head) which runs RB26 intake valves and +1mm oversized custom exhaust valves. It's been decked around 2.5mm (100 thou) and has the ports more open than the head I did above. I floated the valves in this head @ 8500rpm due to old valve springs and the valves got hammered up into the head distorting the valve. I am installing Supertech RB26 intake valves as replacement to the OEM RB26 valves, and the standard Mazda Supertech +1 inconnel Exhaust valves. I'm also upgrading the valve springs to the Supertech heavy duals.
I purchased 2 Neway cutters and have just done all the valve seats with a 4-angle valve job. I also replaced all the valve guides with bronze ones and reamed them out with a 6mm carbide tool.
The cutters I purchased are a 45 / 30 degree cutter and a 70 / 15 degree cutter. They can just do the exhaust valves, but can expand out to do up to 34mm valves too. I also picked up an expanding 6mm pilot guide and an easy turn handle. They are fairly easy to use with the entire head taking around 2 hours to manually do the seats.
All up they come up pretty nice. Intake seats are a bit over 1mm, with the exhaust seats between 1.5 and 1.8mm. It's a fairly easy job for anyone interested in doing this yourself, it just takes a bit of patience. These Neway cutters cost me around the same as taking it to a machine shop and so far I've done 2 heads with them with a third coming up.
Also, the RB26 intake valves fit straight into the Mazda valve guides and if you use the Nissan valve cotters, lock in nicely to the titanium retainers. They are pretty much a direct replacement to the Mazda valves.