Wheels get a bit tricky because folks are often changing a couple things at once when swapping for different ones.
IF you aren't changing wheel diameter or width, the one thing left to "match" is the offset.
Since that is specified in mm., your 1.25" needs to be converted to mm. for an EXACT number you are trying to come close to. Without doing the math, or matching caliper measurements (my favorite double check for the math) 1.25" is about 29mm.
Given the spec. mentioned earlier of 55mm std. offset for your car, this would add up to about 84mm. offset for the wheel in order to leave room for that thick adapter.
Since that is outside the typical range of offsets avail., you can now see why adapters aren't used that often unless someone is going for "Poke" (moving the wheel outwards) which gets into a WHOLE new discussion on fitment, clearance, suspension geometry, bearing life etc..
Before making a decision, I'd suggest reading up on the pro's & con's of such an option.
We usually advocate finding wheels that fit your hubs to avoid this whole issue.
One other thing to keep in mind, a SMALL decrease in offset (additional stick out) is usually acceptable when the sizes don't match exactly. Too much offset is where you have to be very careful to avoid interference between the wheel & struts/calipers/etc..
Reading up on wheels/suspension/etc. can be fun, even for "motorheads", and it's a LOT cheaper than trying things that don't work out the way you'd like them to!