The vanity is 60" wide and the sinks are jammed right up against the walls (with 2" to spare)? That's an odd setup.

Are you planning to put shelves between the mirrors or something? Otherwise I don't understand going to two separate mirrors. Can you post a picture?

If there is only 2" on the side of the sink, and you want the mirror centered, it can only be 4" wider than the width of the sink.

I have a 60" vanity with one sink, set at the end. When I built my house the plumber set the plumbing for the sink much closer to the wall than he was supposed to. I think the sink was 6" from the wall. Anyway, it was very uncomfortable, having to stand right up against the wall to use the sink. Two months later I had it all ripped out to set the sink edge 10" from the wall where it belonged. I couldn't believe the huge difference it made in standing at the sink.

I just checked and I see my powder room sink is 7" from the wall. I don't stand at that sink very often but it seems comfortable enough. I can't imagine a 2" clearance though!

My apologies. There is 4" from the outside edge of each bowl to the edge of the vanity. No plan for shelving in between.

Is there a wall on each end of the counter or is it open? Measure from the edge of the counter to the center of your sink, then double that to get the width you can use for a centered mirror.

LampsPlus has some mirrors.
Other resources: HomeGoods, Tues. Morning, BB&Beyond, Home Depot/Lowes, and stores that specialize in light fixtures are just a few. I've also seen some nice framed mirrors at framing stores.

Here is a link that might be useful: Lampsplus

The vanity bumps up to a wall on the right side and is open on the left side.

Forgot to add the link below. It'll give you some visuals for mirrors over 2 sinks.

Here is a link that might be useful: mirrors

I guess my next question would be whether to do a rectangular or oval mirror over each vanity.

when we redid our bathroom and put both of our sinks together in the same vanity, i thought i wanted 2 separate mirrors... each sink is about 7 1/2 " away from 12" deep towers on each end of the vanity. after alot of thought, i decided it would be too limiting to have to have a relatively narrow mirror above the master bathroom sinks- we put in a large mirror and framed it with mirror molding from our cabinet co.

i was planning to put a sconce in the center of the mirror, between the 2 sinks--eventually, i decided to not even do that- but that was my original plan with the big mirror because one of the main reasons i wanted 2 mirrors was so i could put a sconce between the mirrors. i'm VERY happy we went with 1 mirror!!!-(it's about 60x45- had the shower door co cut and bevel it)