I bought a Trek Triton a few months ago and my head's gone all crazy with upgrade fever. I'm toying with a zillion ideas--all of which are ill-informed and few, I'm sure, will work. I'm tempted to upgrade the brakes (the stock levers and brakes feel pretty chintzy) and I'm wondering what I'm looking at with all this stuff. I was offered a good deal on Ultegra 6700 front and back brakes but I'm feeling a little crazy for two reasons: I'm riding a singlespeed bike and a lot of people seem to toss the back brake anyway, and it looks like I would need to buy new levers. The matching levers are friggin' expensive, I have no idea if cheaper levers are compatible and I have no use for the built-in shifter on a singlespeed. I'd like to upgrade the brakes and I have the money to spend, but it seems like I'm maybe overstepping myself.

Brakes > breaks.

Ah yup. Brakes.

Here is an simple suggestion ... upgrade the pads to KoolStop or SwissStop

You will find the performance is significantly improved without changing the calipers.

The levers you have should be compatible with Ultegra brakes. I think your reference to front brake only on singlespeeds only really applies to fixies. I've never seen a singlespeed with only one brake, just a fixie. If you are only using the bike as a singlespeed, keep the rear brake. It'll be safer. The only reason fixies only have a front brake, is because you can stop the wheel with your legs. If the brakes are at a good price, I'd get them.

If you are running a SS freewheel (not a fixed gear cog), do not remove the rear brake.

Gotcha on the back brake. I realized the mistake after I'd posted. Don't intend to remove the back brake. I'm clearly lost in a haze of unnecessary bike upgrade lust.

As long as you dont have V brakes(they look like this https://www.veryicon.com/icon/png/Tra.../V%20brake.png), which Im 99% sure you dont, your current levers will work fine. While youre changing out brakes though Id go ahead and get new cable and housing. The ultra ones are really nice brakes, and will work well with mediocre levers. Then if you want later you can upgrade to nicer levers.

If you're really set on matching components, Shimano does make levers minus shifters (Level R600). They're still pricey compared to ones you already have.