Speaker Recommendations $2-4k a pair used

I have set up a two-channel system around my 16 year old Thorens TD 320 MKII turntable (with Shure VST III cartridge) that I recently brought out of storage. I purchased a dealer demo Parasound Halo P3 preamplifier and Parasound Halo A1 amplifier from eBay and Audiogon respectively. I am utilizing a set of Paradigm Reference Studio/40 v.2 speakers that I purchased new 7 years ago. These speakers were in my home theater but were replaced there by a pair of Studio/20 v.3's when they did not fit our new family room's built in cabinets. They are on matching sand filled Premier stands. I also purchased new bettercables.com XLR interconnects and speaker wires.

I love the sound of the Studio/40's; they were purchased as a compromise when I could not afford Studio/60's 7 years ago. The only thing I think they are lacking is bottom end, and that not too often. I listen to all types of music - some of my current favorites are Kate Bush Hounds of Love, Indigo Girls self titled, Supertramp Crime of the Century and Allison Krauss and Union Station Live. I also like Metallica, Creed, Pink Floyd and 70's rock bands like Boston, Journey, Styx and REO Speedwagon.

I am looking to replace the Studio/40's with a larger speaker with better bottom end. I am considering Paradigm reference Studio/60's and Studio/100's but would like to consider others. I'm looking for recommendations of other speakers I should consider...
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Why not stay with the line your in now, The reference 6 or 8's
Will supply all the bass you might need. friend drives them with belcanto 1000 monos and bass is very powerful
If you like the Paradigm house sound (which I happen to), why not consider the S8's used? I'm also a big fan of the NHT 3.3's and VR4III's.....
a list of great loudspeakers 'new and used' that won't break your budget and they are keepers. chapman t7, b&w 802s3 matrix, hales revalation 3, psb stratus gold, proac studio 200, castle howard, paridigm studio 100, mordaunt short performance 6,spendor s8, totem forest....all have outstanding balance and are not hard to come across. there are others more rare to find, but none you'll die without.
A used pair of Aerial Acoustic Model 10T speakers would be pretty hard to beat in this price range.