8ba valve train help needed

[Frank Miller]

This should be easy but...
I am putting together an 8ba with a merc crank, nothing special. The last motor I did a number of years ago I got all the stuff from H&H because I figure if they build, then they sell me what they warranty. Figure I got some tech support as well.
Anyway I asked for a 77b cam and they send me this 3/4 grind they do with 274 degrees duration. I sent that back but it took too much time to get a call answered, then Mike tells me he cannot get shit form Isky now. Whatever.
Anyway he sends me the chevy valves with Isky springs that appear to need to be installed at 2 inches to achieve 80 lbs seat pressure. After cutting the valve seats I figure I need a lot of shims and start to do some research. The consensus here is 50lbs is sufficient. These springs will obviously not work at that pressure. I'm not too thrilled about the longer valves either but Mike said it is all he sells.
Now that I have laid out my mistakes, what do I need to do to get on the right track? Obviously I need to buy different springs. Will the chevy valves be a problem or should I just get stock ones to save me the headache?

I'm not really in too much of a rush just trying to do things best I can. Last motor I built I just installed these springs because that is what was recommended. It has not failed me yet but still thinking it could be better.
I guess you can get bad info talking to an experienced builder.

Thanks for any help.