Both are towards "too old" now. It's basically OVER for Intel Macs. Support will rapidly drop off and some question if they will even get the very next macOS update, well under a year from now.
The general timeline for Macs is about 7 years. We're a month from being 5 years into that 7 years. Caveat Emptor!
I suggest separates. Since you are after added power, maybe the new Mac Mini Pro with a nice third-party monitor. Or maybe an M3 MAX MBpro to eventually connect to a bigger third party monitor. If you can stall this purchase for a few months, wait for the new Mini to appear in the Rerfurb store... or seek the approx. same discount in the Edu store.
I'd also suggest you pursue an ultra-wide monitor vs. the iMac/ASD-type squarish monitor. The added width will be very useful for audio track editing. I put the money that could have gone towards an ASD on the
Dell 40" 5K2K ultra wide and could never step back to squarish monitor options. I do both video and audio editing and all that extra width is VERY useful.
But if your attraction to these old iMacs is driven by budget, maybe get a Mac Mini Pro now with a cheap 4K monitor and save up for a better monitor to replace it as soon as you can.