I always kind of thought the greener ones were a little tougher. In my own personal collection, I have a lot of orange and reds but very few greens. I suppose that's all a matter of who you ask though.
In terms of relative availability, I'd view the e93, e95 and e96 sets in one catagory and e98s in a different league altogether. I'd consider those up there with e97s...maybe even e103s in terms of difficulty. Mostly though because of the commons. Seems that HOFers are pretty easy to come by but commons can be a pain.
Just for fun, I threw a scan on here of a few of my e98 "scrap" cards. Got a couple with oversized borders that's been handcut and another that seemingly missed a few print runs (maybe) and now has very little color for whatever reason.
Hope this helps! Good luck Robert!
e98-001.jpg
e98 scrap 001.jpg