Wythnail

I gather you're talking about the deep v rims. If so, finding a new set of rims that have the same exact diameter would be tricky, plus even if you found some, swapping the rim would be tantamount to building a wheel from the spokes up, which is possible. but I wouldn't recommend it unless you do a bunch of reading and learning first.

With buying a new set of wheels with a smaller profile rim, you'd have to buy a rear with a fixed hub. It almost seems like any wheelset marketed to fixies is by default a deep v rim wheelset, and once you find one, it may well by 100+ for both wheels.

Is it really that important to you to have a lower profile rim? The people that will notice that you have deep v rims are also the people that will notice that you only have one gear. That goes in reverse as well, I tend to check out the rear wheel on almost every bike I pass/see in the city out of mild curiosity anyway to see if its a single speed or geared bike.

You could always go the third option: Ride your bike and not give a damn what other people think.