The DP-24, DP-32, DP-24SD, DP-32SD all use SD cards. The model number of the currently available "SD" versions make this a little confusing.
I own two DP-32SD's and one first generation DP-24. <--- For 10 years now. They are excellent recorders. Powerful, intuitive, and reliable. Of course they have limitations. But there are work-arounds and procedural tricks and tips that are not immediately obvious.
A couple of strong suggestions should you go the Tascam DP-24/32SD route:
1) Immediately update the firmware - and use ONLY Tascam approved SD cards. Failure to do this is asking for reliability problems.
2) Watch the Phil Tipping youtube tutorial series. It is incredibly valuable. Phil also sells an inexpensive excellent user's guide.
3) Visit and familiarize yourself with the sticky threads in the DP forum at
www.tascamforums.com. There are tons a tips, tricks, and general recording and procedural advice. <--- super powerful resource
Feel free to ask if you have any questions- although I've moved to Reaper - I still use my DP-32SD for tracking, sketching, and occasionally full songs. I'm very familiar with these recorders.