I just installed scsi and an sd card in my 60 (mkI). The cheapest option I could find was the scsi card from DOPE SHHT ONLY - around £100 from ebay (item # 263064588267) including postage (from Italy), together with a V5 SCSI2SD card which I bought from here -
http://amigakit.leamancomputing.com/cat ... ts_id=1264 - I'm in the UK so this was the cheapest and quickest option, around £65 delivered. You will also need a cable converter or custom cable to connect these together. I didn't realise this until I installed it so I made up my own cable (PITA) but you can buy an adapter board from Artmix for another £50 (total ripoff) here - ebay item # 332315230451. Plus theres the cost of an SD card.
So yeah, it is not cheap to fit scsi, but the speed benefits are probably worth it in the long run. BUT, I find that saving/loading times are still pretty slow (especially for scsi) it is only approx 5x faster than floppy speed. I've used a lot of other samplers with scsi/sd upgrades and they were all much faster, maybe 30-50x speed increase, so the 60 is a slow machine for sure. I also tried it with an external zip drive and the speed was the same.
If your main concern is just getting rid of floppies though, it might be better to just fit a Gotek (HxC flashed type) instead - this will give you the full 780k floppy capacity of the original floppies, not the 720k of a standard Gotek and only costs around £25 (if you do it yourself) and you can store 1000 floppies on a single USB flash drive. It's no faster than a floppy but a lot more reliable and convenient.