There is the Favero SPD Hack option that will come out a bit cheaper than the Garmin pedals, the thread stays pretty up to date on here. Seems like a lot of good experiences with it, up to you personally if you’d trust that with your riding.
Other than that a crank or spider based option can work across bikes, but I highly doubt you’ll find one option that fits across the current bikes. Even finding a match between the Genius and a new XC bike could require a bit of swapping around.
Unless money isn’t a factor for you I’d get a newer XC bike and enjoy that for a long time before going for power. Many people on the forum will tell you that they don’t really use the power on trails like they though they might.