Logic Pro X Hard Drive Question

I have a hardware question. I'm using a late 2013 iMac with 16 gig ram and a standard (not Fusion) 7200 rpm drive. I'm thinking of getting a SS drive and was thinking of replacing my internal drive with it and having the current drive cloned. Or, would it be better to get an external SS drive? Logic has to be on the boot drive doesn't it. Could I put for example my Spectrosonics stuff on an external drive? I don't know about this sort of thing. I write music for license and I find I have to freeze tracks more often.
Thanks for any advice,
I have a late 2013 iMac with a Fusion drive. If you have the USB port for it (no hub, directly to the iMac) I would use an external SSD. Clone the internal disk to the SSD (Carbon Copy Cloner), then boot from the SSD. I built a system on an external SSD for various reasons and tested the ensuing system with BlackMagic Disk Speed Test (from the Mac App Store). My external SSD gets write rate of 250 Mbytes/second, read better than that. My Fusion drive gets the same write speed, and similar read speeds.

Get the speed test program and see how fast your internal disk is. I suspect that it is nowhere close to the speed of an external SSD on a dedicated USB port.

Get a 2TB disk, put everything on it, and save your Logic projects on the internal disk...after you finish working on them.

Added benefit is you can take the SSD anywhere and run on pretty much any Mac that you can connect it to. I can use my small Logic SSD system on all of my Macs (all 2014 and older) perfectly well. No issues. Performance as good as my speedy iMac. Of course my next system will be a 2TB Mac mini with read/write disk speeds of 2,400 Mbytes per second. A DVD every 2 seconds ;-)