Well I live in Salem and I have never been to Homebrew heaven but I don't know why you couldn't go there I just think they probably don't have everything you would want all of the time. I went to OSU so I've always went to Corvallis brewing supply. Joel is super helpful and friendly, they have a lot of stuff so you should be able to find what you need on any given day. I actually worked there for a short time and from what I could see their price structure was totally fair. Other thing is, he has a bottle shop, there are no bottle shops in Salem, so if you want some specialty beers you out of luck in Salem. I can get to Corvallis in 45-50 min which is closer than Portland and has a lot less traffic, also there is two breweries you can visit on your trip, Calappoia in Albany and Block 15 in Corvallis.
EDIT: by the way if you ever want to get together to brew let me know, it's nice to see someone else who will be from Salem. By the way there is a homebrew club in Salem called the Capital brewers, I wasn't a big fan but that may just be my personality. If I had the time I'd probably go with Heart of the Valley Homebrewers out of Corvallis or the Oregon Brewcrew out of Portland.