Need recommendations for a Step Up Transformer for Denon 103


I have a Denon 103 that needs a SUT. I'm told that the Denon performs best when loaded with 470ohms. I'm new to the world of SUTs and would appreciate recommendations on a SUT that can achieve this specific loading or one close to it. My budgiet is ~$500 but preferably less. I've heard good things about the Ortofon ST-7, Parks Audio Budgie SUT, and the Rothwell MCL...
dptv
Any of the Denon SUT's will work fine. I have one in use with a 103R. Along with a Bellari and a Quicksilver plus three others (Sony T10 and two custom-built with mic transformers). Loading is a matter of personal preference for mc's - experiment and listen!
This was designed, with your cart in mind: http://www.auditorium-23.de/Accessories/Transformers.html I have one and it works very nicely, with my Denon(ancient/classic) 103D and Dynavector 17D3 carts. https://6moons.com/audioreviews/auditorium23/23_3.html Bought it from: https://donbetteraudio.com/accessories/  Used are available and in your price range.
Parks Audio Budgie is what I used when having an SUT in my system. It is VERY good. Dynamic & smooth. It uses CineMag transformers, which is what Bob uses in his more expensive SUT's. 
Parks Audio no longer makes the Budgie. The new unit is the Puffin which doesn't use the Cinemag transformers. Besides the Denon SUT which are very good I would also check out the Rothwell SUT'S.