Need advice about hi-end amp/pre-amp

I am considering going back to separates. Presently, I have a Creek SE5350 Classic integrated amp which is very good, but other members have suggested other IA like the Naim XS and Prima Luna Dialogue Two. However, I believe some separate combos may over a "discernible" improvement in sound. I know the tradeoffs of a good integrated versus separates. I may need to spend a lot of money to make a difference in performance over the Creek. I will probably shoot for good used pieces and to stretch my budget, considerng I will trade on sell the Creek. 100 RMS is enough power. The new setup will probably have Zen Acoustic's Adagio's. I currently have a new Rega Apollo player and a Rega P3-24 table with a Dynavector 10X5 which so far look like keepers. I will probably outboard the phono stage. In the past, and for 19 years, I owned the Aragon 4004MKII amp and the Conrad Johnson PV-8 pre-amp which was modified for lower noise. The sound of this combo was generally very very good,though somewhat bright and a tad edgy..... All advice and comments welcomed.
Other than wanting to try something else, what are you looking to improve by replacing the Creek?

A used Rega Mira 3 would be a great match for the rest of your equipment.
agree with rar1...the creek plays way way over its price, so you must want to change something...maybe its not the amp? wait until you have firmed up the speaker choice, and given that some time.
I agree with Jaybo;get your speakers first, then amp(s) and preamp last.
Rar, Jaybo and others. The Creek is excellent in many respects. I can't generally fault its performance. Though, it can sound bright and a tad edgy, but there are other factors in the system and my new living room space which are contributing to the brightness The Creek is very accurate, but is it euphonic?? or that overworked term "musical" On this issue, I once purchased on the 'Gon an almost mint Musical Fidelity X-150 integrated amp which was compact in size and provided 75RMS. I was considering downsizing from the Aragon amp and CJ preamp. At the time I had Vandersteen 1C's which sounded very good. Here is my point, the Musical Fidelity almost always sounded musical and satisfying to my ear. I was often amazed at its ability to hold my attention. Without a doubt, the Aragon and CJ combo bested it in many areas, however, I still think the X-150 was more satisfying to listen to. It sounded "right". I eventually sold it because the inboard phono board was only fair and often sounded harsh. I experienced the same type of "rightness" in auditioning a pair of Epos 12 monitors about two years ago, and also (don't laugh, the Large Advent speakers---I went retro for six months)....I agree with those members who advised checking out speakers first. As you probably saw from my previous posts, I have the Silverline Prelude II which are good sounding and very dynamic, but their upper mids and highs seem forward and literally over the top. Nothing I have in the last couple of years owned can match the B&W Matrix 3MKII that I owned for 15 years---that was a high end speaker. I need to get back into that acoustic ballpark..... Thanks again for the comments and advice. Jim
once the new speakers are in place and the creek gets a shot, then change if you feel the need. i would recommend auditioning the new anthem 2 channel integrated for a 'blast from the past' full feature, organic sounding unit that may be as pleasing to you as the mf.