As usual, you're getting great information. Bogie, Moosecountry and most of the folks on here know a lot more than I do, but I try to give what information I think I know nonetheless.
Like Moosecountry said, home porting can get a relatively novice guy (like you or I) into trouble if we aren't careful. If you go ahead with a better valve job, a bowl blend and taking any edges off of the short turns shouldn't be enough to get you into trouble. Even though aluminum clogs up sandpaper rolls pretty quickly, I would use them to get the job done. You shouldn't have to remove too much material and the sandpaper rolls help to avoid taking too much away too quickly.
As Bogie mentioned not enough people pay attention to measuring things. The lifter bores (and bores in the cam tunnel) seem to get overlooked. The thrust button or thrust plate is a must for me as well. Even on flat tappets. Along with helping with wear on the cam and lifters, I think it helps out the timing chain stretching.
If you don't have a degree wheel, that's also a must. As Moosecountry alluded to, getting the cam where it needs be is critical. Just making sure the cam is what it's supposed to be is important too.
At the projected power level you have here, what do you know about the transmission? If it's not a "built" unit already, there are some pretty budget friendly upgrades to be made there that do not require the transmission to be fully disassembled or even removed from the car.
If you're running the factory rear end there are things to consider too.