The alternative -- depending on how often you use diacritics -- is to print out and tape up a list of alt characters, and then switch to the US default keyboard layout. This solution is massively cumbersome if you frequently use Swedish, but is good enough for people who work mostly in English but use the occasional diacritic character.
..although this is a comprehensive list that you'd want to pare down.
More expensively, you could buy a gaming keyboard with a macro pad or a standalone macro pad, something like:
(have never used either of those myself, though I know gamers tend to like the sidewinder well enough.)
...and assign all the macros keys to the alt-key combinations you use (that is, assign G1 to alt+160 = á, shift+G1 to alt+0193 = Á, ctrl/alt+G1 to something else, etc). Then buy an international keyboard sticker set, and stick the appropriate stickers onto the macro keys to remind you what key does what. Then you can use the US default keyboard layout with the correct quote key functioning, while still typing your Swedish letters through the macro keys.
Probably easier to train yourself to hit the spacebar or continue using your keyboard swap workaround.