@Pars , @n_maher , thank you both for the assistance. I guess it's clear I need it
Regarding the DC to DC converter, I didn't so much think I needed it as it might be ultra overkill for voltage regulation to ensure clean power. However, maybe a regulated DC supply is a more efficient option here, both in cost and building...
If I used an AC transformer i would be sure to convert to DC, which I was considering, but now after thinking it over some more, it seems silly not to just use a DC supply.
Lastly about that SOIC adapter, many thanks for those points @Pars as I didn't even consider the speed issue. The amp has one OPA134 on board. There's nothing wrong with it at all - the desire to affix a DIP adapter where it was is entirely FOTM. I wouldn't be opposed to leaving the OPA134's on board. Seemed like a fun extra thing to do for the heck of it, but never was a priority really.
Thanks again very much to both of you for steering me in a more reasonable direction!