I like SB-7 over the 11. Its cheaper and I tend to get more hits with the 7 than the 11. Also its more compact and just easier to work with. The SB-7 I have came with a speaker because on its own its very quiet. You'll want to get something with an AUX cable that you can connect it into. Be aware that the BLUE backlite version is the older version and the RED is the new ones.
Here is the one I have. https://www.amazon.com/Spirit-Orbital-Bluetooth-Universal-Speaker/dp/B00WKBP9OY/ref=sr_1_2?crid=3W3SUMD1IV1Q1&keywords=Spirit+box&qid=1645582375&sprefix=spirit+box%2Caps%2C104&sr=8-2
Personally I don't like phone apps. My friend has a cousin that makes fake apps and its super annoying. I once tested an SB7 app in my home (not haunted) and without even asking answers every minute I got a yes or a no. So if your gonna use one go somewhere you know isn't haunted and see what you get before taking it into the field.
Be aware that the PSB7 is ANNOYING! I do YouTube so I experience it in the field and then once again when editing. It became so Annoying I purchased a Portal Device that works with my P-SB7 and it gets rid of the annoying sweeping! Now these can be expensive depending on where your looking. I got mine from Gotcha Ghost for about $350 for a small compact version. (These do not come with an SB-7) If your curious on how they sound I have multiple videos of me using it on my channel. But I think some of the best represented responses came through at Waverly Hills.