Upgrade Advice

Hi All

Looking to upgrade my audio/HT system

I have:
Denon AVR 4311CI
Mirage OS-FS (v2 I think) for fronts
Mirage Omnistats x 4 for surround L+R and Front Wide L+R
Mirage nanosats fore rear
Mirage OS3-CC center
SVS SB13-Ultra sub.

I love the sub and am planning a second.

I use it for HT 80% of the time and music 20%. Music source is normally lossless rips of CD's or downloads from iTunes via Sonos to Denon via optical. I listen to mostly contemporary music. Have a few SACDs (Sony S790 Blu-ray)

I would like to lose the floor standing speakers because of space/aesthetic issues and replace with good quality bookshelf speakers that would work well with the SVS. Given that the sub is always used, will I miss much doing this? I do have a pare set of the Mirage bookshelf speakers

Also considering separate power amps like Emotiva XPA-2. Is this pointless with bookshelf speakers? Would better amp be better than better speakers (given the speakers I have)

What would be best upgrade for a few thousand now and some more later? Should I go with external amps first and then new speakers or vice versa?

I can live without the rear speakers, as there is very little content in 7.1
Sorry, that should have said Emotiva XPA-100
Typically the biggest impact on your sound will occur if you upgrade the speakers. Then you buy an amp with your speakers in mind (obviously you won't buy speakers that are incompatible with your current gear), the sources etc. upstream. In reality after you improve your speakers the remaining upgrades may occur in any order.