Rethm Bhava is less finicky about amp pairing as well, any SS amp of 40 w + should be able to drive them with ease (according to brand owner Jacob) , the top driver is full range which is easier to drive and the woofer is anyways powered with its own amp circuit. I listened to the Setup at Kochi with Tube Pre-power setup. There are many aspirants for Rethm Bhava on the forum , if all could work out a group buy it'll be great.
You could consider Lyrita DHt tube preamp (almost 40k INR, but you're saving 25k out of your budget for speakers) with a SS power amp. Actually, I was considering this tube preamp from Lyrita but postponed due to year end financial commitments. Other tube amps from Lyrita can be considered as well, the tube amp for Rethm audition @Kochi was of 10W power if I remember correctly.
I don't think lack of a speaker grill for only top driver shouldn't matter much, one can be made locally if required.