E-Tec 170s are not a copy of the Vortecs.
They have stainless valves, you can run 1.6 roller rockers, you can stuff in big springs, they have a bigger exhaust valve, good bowl work, and flow ~80% E/I ratio.
Go with the 200s, you will be all good.
However that cam is a bit mismatched with that huge exhaust spread.
Both the E-Tec 170s and 200s have great E/I ratios, a cam with a smaller spread in duration or a single pattern cam would suit you best.
I got the 170s on my motor, when I bought the heads I only had 1 5/8" headers, the 200s require 1 7/8" headers, which I have now.
So if I had the choice again it would 200s but I have no problem making a bunch of power with the 170s.
However without a cam change, if you stick with the Hotcam, your numbers will not change a whole bunch from what they are now.
READ THIS: http://www.carcraft.com/techarticles/56978/index.html