Tube MC phono stage recommendation

That's fair. Most of the carts I would likely start with would be in the 0.5mV - 1.0mV range. 

Sonic Frontiers was not on my radar, will take a look for sure. Thanks! 

Sonic Frontiers is unfortunately defunct, but the head guy behind it now runs Parts Connexion, and he offers service plus upgrades on Sonic Frontiers gear. I’ve been through a number of phono stages by now, and the Phono 1 has impressed me the most in its "value for money" - yes, even compared to the Herron phono stage (which is excellent but priced a full level above). There is that caveat your output must be close to 0.5mV or higher, but looks like you’re there so I’d keep my eyes peeled. Mine is staying here for the forseeable future; it's unbeatable in my 2nd system :)

Happy New Year!

An alternative to the excellent ideas above would be adding high grade Cinemag step up transformers to your EROS, or something from Bobs Devices, I am sure this has been done, see the Bottlehead forum....

Second what tomic601 said.  If you built the bottlehead,  doing a sut would be a Breeze.  Also if you still want to change amps,  you will be MC ready.

Enjoy the ride
Tom

@tomic601 's suggestion for a Bob's Devices / CineMag SUT is a great one, and all of the blue-label models sound fantastic - 1254, 1131, Sky (in various ratios). Bob's Devices makes many of these (the Sky and 1131 models are exclusive to him) and they show up used for a good price occasionally. I've used a total of 4 of these and really liked each one. I think even the old CineMag 3440A came in a blue-label version for a short time. I'm not a huge fan of the old red-label 3440A, but even that model would make a huge improvement on your current setup, with your existing phono stage. You'll get dynamic, bass impact, clean tone - all with a much lower noise floor to boot. The only devil to tack down with a SUT is ground hum - and you IC cables from SUT to phono stage should be kept short as possible (less than 1m is best), low-capacitance, and shielded!