Top vintage receivers vs. modern high-end equipment

Look at Ear 509 monoblocks from the ‘90s: i never heared a better poweramp like that!!!

Your answer really depends on what you want to accomplish.  First- AVOID a vintage receiver !   Even a fully restored Fisher 500c or Mac 1500 will not be good enough for your speakers !

Do you want vintage tube ?   Heath W5m, Eico HF 50 or HF 60 monoblocks.   Fisher 50a or 90 monoblocks.  Of course anything from a Mac MC30 to MC75, and MC240, MC275 would work.  Harman Kardon Citation II  aka "The Duece" would be ideal !  

For a preamp- some swear by Marantz 7c, or Mac C20/22.  Some love the Citation I, or Fisher 400cx.

Do you want vintage SS ?   Mac SS equipment is well regarded, dead solid reliable and tends to sound good- after a careful restoration.  A sleeper is the Mac MC250 / their first SS amp and it sounds like a mix between a tube amp and solid state.  A Marantz Model 15 is another under rated amp- it is actually a pr of mono blocks on a common chassis- ONLY parts shared are the faceplate and power cord.  

For a preamp you have a lot of choices.  If Mac I would not consider a C24 or C26; it is only with the c28 that Mac produced a good smooth and excellent sounding preamp.  Again, caveats of restoration apply.  Some say a fully restored Marantz 7T also can sound very good.

Newer equipment can sound good with your speakers.  Most Audio Research tube amps and their classic tube preamps would be ideal matches.  Vintage Luxman.  Vintage Accuphase.    Both good choices.

If it were me- I would go all tube !

Lot of choices- but stay away from receivers !

I have a JBL Metregon, your Paragon's little brother.  We are both very lucky people!Both the Metregon and Paragon are pretty efficient and I have run mine with both tubes and ss.  With the Prima Luna Prologue 6 monos (with either Psvanes KT 88 Mk II IIseries or  JJ E34L Blues the sound is as you would expect very tube like.  Warm and rich with the E34Ls I think surpassing the KT88s in a very sweet and detailed midrange. The power difference isn't that great between the 2 sets and the Paragon doesn't need it anyways.  The KT88s have a slightly deeper defined bottom end. I ran a friends' 12 w tube amp to demonstrate it for him and the Metregon could still blow out the room.
I have many hours running the Metregon with a Pioneer SX1050 (fully refurbished) and because the 1050 was designed to be tube like there is very little difference except because of the 1050s power the bass is stronger and I think more detailed.  The mids and highs are very nice and certainly very acceptable but not in the cat of either tube set. I think the horns like the tubes better.So take this for what it is worth, I really don't think you can wrong either way
Best 
Mark

psI use a Jolida tube pre with the PLs

I'm not saying you should get one , it's not the best by any means but some of these old amps have a non audiophile magic. I acquired a Mapleshade Scott LK48 not really knowing what it was. I brought it to work hooked it up to some Paradigm very first generation Atoms speakers, a 2 or $300 speaker, source was an old Denon DVD player. I hit play and could not believe those Atoms could sound like that. I brought it back home that same day. Hooked it up to some Usher tiny dancer and with jazz, blues or non complex music there is a very natural presentation that addicting. No big bass or super detail.