Rethinking my Current System

This is combo question, fitting for IEMs, Computer Audio, and Amps and Dacs.

What I have:

Old Ety 4S/P IEMs and an old Headroom TotalAirHead that connects an old iPod via a Sik cable.

I also have AudioEngine A2's connected to the audio out on an iMac.

What I like:

Sound on the 4S, especially when using the TotalAIrHead. Though I have little for comparison.

What I don't like:

Current sound on the A2's. I liked the A2 sound better on my old computer when connected to the Creative EMU 0404. However, since the EMU software doesn't work in 64-bit mode on my iMac (don't want to step down to 32-bit mode), I sold the EMU 0404.

The feel of the deep 4S/P insertion into my ears after about 10 minutes.

The TotalAirHead is old, and the 3 AAA batteries often slip and lose connection.

The Ideal Solution:

Comfortable IEMs

A DAC/headphone amp I can connect both to my computer for A2 use, and a portable DAC/AMP to boot.

Ideas:

Comply tips

Custom tip (Westone 56?)

uDAC-2

iBasso D-Zero (ablity to drive my A2's?)

better DAC/headphone amp combos?

separate DAC for computer and newer headphone amp?

Replace Ety 4s/p with HiFiMan REZero

Before I got too far with the blind (me) leading the blind (me) I thought I'd solicit your help. I'd like to keep costs to a minimum, but for now I'm not sure how much money that means.

Thanks for your help.

Michael

Wow. The more I read the more confusing this all becomes.

I looked into the Fiio e7 +e9 combo. It seems that the weak link is the e7, soon to be updated by the e17 in February. However, from what I understand, the e7 + e9 combo will output power (amp) and dac away from my computer soundcard to power m7 AudioEngline A2s. Also, the e7 alone will replace my TotalAirHead for portable use. Very nice. Are there other amp/dacs with similar function? I'd also like to be able to control the volume using the external amp; I want to bypass my Mac keyboard, and the volume on the A2 is hard to reach.

As for IEMs, it seems that keeping the Ety ER-4s is the best option, that is if I can find a tip that is more comfortable than the 3- finned flange. Do the Ety customs work well while maintaining excellent sound and isolation? How about the Shure Olives?

Is it better to keep the er4 and spend $100 for custom tips, or just buy a newer iem? If newer, what phones woulld have similar detail as the etys, operate well amped and unamped, and fit comfortably in the ear? If I go newer, I'd probably sell the ety.