I can't find what your pre is Dev.
If you'd be willing to forgo the pre, I'm thinking that you should seriously consider the Rowland Continuum 500, which gives you a great pre, power factor correction and most of the circuit of the 312, all for much less than the cost of a Capri/501 monos/PFC combination.
If you want to stay with your pre, then consider the 501s PLUS Power Factor Correction. Try to run everything balanced and see what you think. With luck you can find some used 501s here on A'gon and add PFC.
Few of us need the power of the mono Spectrons, but, if you do, there's very few substitutes right now. My experience with the Continuum shows me that huge reserves of power is a good thing, at least when the power is clean, transparent and non-punitive (as with some older SS amps in other classes).
Dave