which budget integrated amp Rotel, NAD or other

Rega products are said to be nice, although I have no direct experience. The Rotel integrated amps do have a phono stage, which was another nice plus over NAD for me. I don't know about those Usher speakers (a dealer I visited did have a pair of Usher something-or-others hooked up to an Integra for demo purposes, but that's my sole experience with Ushers), but the 60 W Rotel RA-1520 was driving a pair of B&Ws in the dealer's, and B&W speakers are generally known for being wattage-happy. The dealer I bought from also said that the Rotel (also a similarly-spec'd NAD) should have no problem driving my very inefficient Smaller Advents. (I haven't hooked it up yet to test because my Advents are still in the shop.) So I don't think you Ushers should be an issue.

The Brio 3 should drive those Ushers without a problem.
The binding posts and RCA connections are not the highest quality, unfortunately. The source select and volume pots also feel a little cheesy, but they work fine.

One of the best integrated within $1.5k budget for me was used Krell KAV300i. It might be more expencive, but often available used and obviously better for Usher than above mentioned Nads, Rotels and Regas.

Perhaps an intergrated from Musical Fidelity? The A3.2 has 115 watts per and phono. Any comments on this?

One of the best integrated within $1.5k budget for me was used Krell KAV300i. It might be more expencive, but often available used and obviously better for Usher than above mentioned Nads, Rotels and Regas.