Recommendation for a 300b Integrated amp

Good suggestions above. I'd strongly consider the Audio Note Kit 300b SET with the upgraded double C core output transformers. You can have it built by Digital Pete if you don't want to build it yourself. Roxy54 has this amplifier and says its excellent sounding. His was built by Pete. The VAC REN 30/30 is a very good amp but is push pull. It will be a bit different from a SET presentation. Not saying better or worse but a different sound presentation. Just depends on what you're looking for. In your price range you have many good choices.
Charles,

Wow! just noticed a Viva 300b PSET for sale on this site. I hardly ever see these available.Viva amplifiers have very stout power supplies and very good transformers.Interesting.

Jarrett,
If you are serious about getting a 300b amp, there are some compelling choices for sale on this site. The Allnic 1500 and he's offering pair of EML XLS for an addition 400.00(a true bargain for these superb 300bs).

I see a pair of Wavelength Cardinal (PSET version) mono blocks available. You have some seriously fine choices at terrific used prices. These two amps and the Viva mentioned above would be an excellent foundation for a SET based system. Your timing is good.
Charles,