ORIGINAL: Rodney
If you can not get spruce try pine. If you have a lumber yard that will let you select the stock, you can often find some close and straight grained pine boards that can be ripped into pretty nice spar stock, I do it all the time and I'll bet you can not tell the difference between them and spruce ones in either looks or strength. It just takes a lot of looking and choosing those boards with little or no pitch and nice close straight grain.
I've used pine as well, but I've found it to be much heavier than spruce. I've now gone back to spruce for spars but still use pine where I need small blocks of hardwood (harder than balsa anyway) for mounting things like servos, struts, etc.